info.json must have correct @id

[line-o]

Request to info.json for example image

http://localhost:8000/cgi-bin/fcgi-bin/iipsrv.fcgi?IIIF=imageStorage%2Fecpo_new%2Fimage2.tif%2Finfo.json

yields

{
  "@context" : "http://iiif.io/api/image/2/context.json",
  "protocol" : "http://iiif.io/api/image",
  "width" : 4290,
  "height" : 2994,
  "sizes" : [
     { "width" : 67, "height" : 46 },
     { "width" : 134, "height" : 93 },
     { "width" : 268, "height" : 187 },
     { "width" : 536, "height" : 374 },
     { "width" : 1072, "height" : 748 },
     { "width" : 2145, "height" : 1497 }
  ],
  "tiles" : [
     { "width" : 256, "height" : 256, "scaleFactors" : [ 1, 2, 4, 8, 16, 32, 64 ] }
  ],
  "@id" : "http://localhost:8000/cgi-bin/fcgi-bin/iipsrv.fcgi?IIIF=imageStorage/ecpo_new/image2.tif%2",
  "profile" : [
     "http://iiif.io/api/image/2/level1",
     { "formats" : [ "jpg" ],
       "qualities" : ["native","color","gray","bitonal"],
       "supports" : ["regionByPct","regionSquare","sizeByForcedWh","sizeByWh","sizeAboveFull","sizeUpscaling","rotationBy90s","mirroring"],
       "maxWidth" : 3000,
       "maxHeight" : 3000
     }
  ]
}

note the value of the @id property.

1. MUST have the the correct link to the requested file (the domain that was requested from)
2. MUST have full link to file not %2 at the end

[duncdrum]

see #10, add tests for both cgi and non cgi requests