Add decltype header

Expose decltype on pre-C++11 compilers. Currently just aliases decltype
to __decltype.
euler: use function pointers to select kernel
Improve handling of GPUSPH_VERSION in case of git failure
SED_COMAND -> SED_COMMAND
Fixing compiler issues. Dambreak with LJ seems to be working nicely.
Fixing positions for compute capability >= 20
Merge branch 'user/bilotta/candidate-master' into sa-bcs

Conflicts:
	src/Problem.cc
	src/Problem.h
	src/StillWater.cc
	src/StillWater.h
	src/euler.cu
Merge remote-tracking branch 'origin/user/herault/homogeneous_precision' into candidate-master

This introduces the fixes to the Paddle and WaveTank.

Conflicts:
	src/WaveTank.cc
	src/particledefine.h
euler: paddle fix for non-zero origin
euler: missed another world origin issue (objects)
Minor tab formatting and comment cleanup
WIP: added initial ODE support (not connected now with force on objects
computed on GPU)
Conflicts:
	src/ParticleSystem.cc
	src/Problem.h
	src/particledefine.h
Solved conflict forgotten in 4a0745ecef
Added -DdSINGLE for ODE compilation
WIP: ODE version with working example with hinge
Conflicts:
	src/ParticleSystem.cc
	src/Problem.cc
	src/Problem.h
	src/euler_kernel.def
	src/forces_kernel.def
Added ODE types support
Added ODE types support and rotation with ODE matrix
Added rotation with ODE matrix
Corrceted constructor from float* and double*: should be const
Added TransposeRot method.