Fix elevation

[barbeau]

Currently we've removed elevation for now, since we're not using it and it causes
version conflicts between v0.9.1-SNAPSHOT and v0.9.2-SNAPSHOT.

https://github.com/CUTR-at-USF/opentripplanner-pojos/blob/master/src/org/opentripplanner/v092snapshot/api/model/Elevation.java

Here's how Elevation looks in v0.9.1-SNAPSHOT, from Portland's OTP instance:
"steps":[
{
"distance":23.768848496536464,
"relativeDirection":null,
"streetName":"West Burnside Street",
"absoluteDirection":"WEST",
"exit":null,
"stayOn":false,
"bogusName":false,
"lon":-122.67618121575384,
"lat":45.523010297969236,
"elevation":"0,-12.4,8,-12.4,18,-12.4,24,-12.5"
},

Here's how it looks in v0.9.2-SNAPSHOT, from Tampa OTP instance:
"steps":[
{
"distance":396.7624311389624,
"relativeDirection":null,
"streetName":"path",
"absoluteDirection":"WEST",
"exit":null,
"stayOn":false,
"bogusName":false,
"lon":-82.41010169697705,
"lat":28.066668266868074,
"elevation":[
{
"first":0.0,
"second":-12.398322105407715
},
{
"first":8.822516441345215,
"second":-12.383489608764648
},
{
"first":17.15460777282715,
"second":-12.262986183166504
},
{
"first":34.30921420775514,
"second":-12.262986354701583
},
{
"first":44.043828136544064,
"second":-12.333215802985222
},
{
"first":44.043828136544064,
"second":-12.333215802985222
},
{
"first":54.043828136544064,
"second":-12.296236471306694
},
{
"first":66.02274363670121,
"second":-12.201396218572842
},
{
"first":66.02274363670121,
"second":-12.201396218572842
},
{
"first":75.88727719493157,
"second":-12.041203691359716
},
{
"first":75.88727719493157,
"second":-12.041203691359716
},
{
"first":90.31092492990427,
"second":-11.817913619117205
},
{
"first":90.31092492990427,
"second":-11.817913619117205
},
{
"first":93.68013649532344,
"second":-11.588739306256882
},
{
"first":93.68013649532344,
"second":-11.588739306256882
},
{
"first":102.75202277237338,
"second":-11.402049342205405
},
{
"first":102.75202277237338,
"second":-11.402049342205405
},
{
"first":109.32474010940426,
"second":-11.095196224271241
},
{
"first":109.32474010940426,
"second":-11.095196224271241
},
{
"first":119.32474010940426,
"second":-10.615473135000219
},
{
"first":129.32474010940427,
"second":-10.183085539859187
},
{
"first":136.41064711308425,
"second":-9.883945841688735
},
{
"first":136.41064711288388,
"second":-9.883945841688735
},
{
"first":146.41064711288388,
"second":-9.492437843790363
},
{
"first":156.41064711288388,
"second":-9.246165386481941
},
{
"first":166.41064711288388,
"second":-9.091391475256192
},
{
"first":176.41064711288388,
"second":-8.972897387290224
},
{
"first":185.9405614027797,
"second":-8.903510633267153
},
{
"first":185.9405614028022,
"second":-8.903510633267153
},
{
"first":187.39519074054814,
"second":-8.957065252640824
},
{
"first":187.39519074054814,
"second":-8.957065252640824
},
{
"first":197.39519074054814,
"second":-9.346189918622684
},
{
"first":207.39519074054814,
"second":-9.705159995913514
},
{
"first":213.33719663742332,
"second":-9.988953654311649
},
{
"first":213.33719663811462,
"second":-9.988953654311649
},
{
"first":223.33719663811462,
"second":-9.785574537058231
},
{
"first":233.33719663811462,
"second":-9.746729684360446
},
{
"first":242.84306889153657,
"second":-9.797070838063444
},
{
"first":242.84306889153657,
"second":-9.797070838063444
},
{
"first":252.84306889153657,
"second":-10.21064449148886
},
{
"first":265.3011469192453,
"second":-10.512517269671841
},
{
"first":265.3011469192453,
"second":-10.512517269671841
},
{
"first":278.162188257261,
"second":-10.489122368351229
},
{
"first":278.162188257261,
"second":-10.489122368351229
},
{
"first":290.02339402191177,
"second":-10.683903242293837
},
{
"first":290.02339402191177,
"second":-10.683903242293837
},
{
"first":295.14168840401646,
"second":-10.87621605932458
},
{
"first":295.14168840401646,
"second":-10.87621605932458
},
{
"first":303.5591575633344,
"second":-11.093963084461764
},
{
"first":303.5591575633344,
"second":-11.093963084461764
},
{
"first":313.5591575633344,
"second":-11.358763357682777
},
{
"first":319.1485253067458,
"second":-11.5023243236003
},
{
"first":319.14852530653593,
"second":-11.5023243236003
},
{
"first":329.14852530653593,
"second":-11.370142391499558
},
{
"first":339.1254360206949,
"second":-11.125468363383614
},
{
"first":339.1254360206949,
"second":-11.125468363383614
},
{
"first":341.7537643725829,
"second":-11.173147301457039
},
{
"first":341.7537643725829,
"second":-11.173147301457039
},
{
"first":351.7537643725829,
"second":-10.863938742080276
},
{
"first":361.7537643725829,
"second":-10.562463712264842
},
{
"first":372.2989617661212,
"second":-10.124440043371312
},
{
"first":372.29896176605536,
"second":-10.124440043371312
},
{
"first":382.29896176605536,
"second":-9.493728356616474
},
{
"first":389.286544316315,
"second":-9.057712546749627
},
{
"first":389.28654431631236,
"second":-9.057712546749627
},
{
"first":399.28654431631236,
"second":-9.364346606417264
},
{
"first":406.4109946793275,
"second":-9.68683439522605
},
{
"first":406.4109946790731,
"second":-9.68683439522605
},
{
"first":413.91703824284,
"second":-9.429762063790795
}
],
"alerts":null
}

[vreixo]

I will look on this, because I have successfully added elevation to A Coruña and I really would like to take advantage of it. I'm also thinking in represent in same way the resultant elevation profile (witch I suppose that is the data present in elevation field).