Merge branch 'master' of github.com:SimonRit/RTK
Taken from ITK 4.2.0
Merge branch 'master' of github.com:SimonRit/RTK
Missing include for ThreadIdType
Fixed multithreading bug
Improved forward projection test
Improved forward projection test
Added test for the forward projector using itk ray cast interpolator
Merge branch 'master' of github.com:SimonRit/RTK

Conflicts:
	testing/rtkforwardprojectiontest.cxx
Fixed compilation issue in debug mode
Fixed compilation issue in debug mode
Merge branch 'master' of github.com:SimonRit/RTK
Fixed bug when drawshepploganfilter is not used in place
Raised tolerance
Fixed installation code
Fixed bug in geometry file writer
Added geometry file test
Fixed bug with SourceOffsets
Various fixes taken from VV v1.3
Some fixes taken from Plastimatch