Add localEqual, but had to use a different operator.

The three equals (===) conflicts with the ScalaTest ===.
I made it ==== for now. I'm not sure how to resolve this.
Add localUnequal.
Add localGreater.
Fix a bug with right associative localGreater.
Add localLess.
Add missing test to GreaterSpec.
Add localGreaterOrEqual.
Add localLessOrEqual.
Add localAbs.
Add localSinh.
Add localSin.
Add localCos.
Add localTan.
Add localArcSin/Cos/Tan.
Add localAtan2.
Add local hyperbolic cos and tan.
Merge branch 'master' into localops
Merge branch 'master' into localops

Conflicts:
	core/src/main/scala/geotrellis/Raster.scala
	core/src/main/scala/geotrellis/raster/op/local/Asin.scala
	core/src/main/scala/geotrellis/raster/op/local/Tan.scala
Refactor local methods.

  * Move one liners into LocalMethods.scala
  * Add Raster/RasterSource result type to signatures
  * Remove ==== operator from Equal
Add result types to localIf.