Proj Speed Up (#479)

* Moved around model construction

* Added verbose option to usgscsm_cam_test

* Cleaned up model instantiation

* Fixed warning from getUsgsModel function

* Removed commented out code

* Removed last line of commented out code

* Fix linux builds

* Removed m_camera delete on reset

* Proj sensor now carries an identifier for the underlying csm model

* Added basic projected sensor model tests

* Added warning for users using the projected model

* Hide dependent library symbols

* Defined proj env var

* Adjusted proj camera tests for specific OSs

* Set proj data dir in tests

* Fixed ConstVelocityProjectedSensorModel, RemoteImageLocus test

* Removed duplicate comment from other test