use MPI_Abort in comm_abort
Removed unnecessary fat-link linkage in hisq force tests.
Fixed bug in multi-GPU staggered outer product code.
Fixed referencing bug affecting CPS and MILC gauge field wrappers.
Check that gauge field order is supported for gauge_force_test.
Fixed typo.
Typo and compiler warning fix.
Removed old gauge force interface code.
Fixed bug in single-GPU gauge-force interface code.
Removed warnings when compiling without s-step solvers enabled.
fixed bug for the non-degenerate twisted mass dslash (need to check it)
Fixed bulk and ghost thread setting for twisted clover fermions.
Merge branch 'quda-0.7' of https://github.com/lattice/quda into quda-0.7
Merge remote-tracking branch 'origin/quda-0.7' into gpu_comms_debug

Conflicts:
	lib/dslash_twisted_mass.cu
	lib/staggered_oprod.cu
Degenerate twisted mass now works with the fused ghost array.
Non-degenerate twisted mass needs work.
Unfused staggered dslash works with the ghost field in single and double
precision. Half precision needs some modification to work.
Unfused half-precision staggered dslash now works
Fused staggered kernel now works with ghost array
Domain-dslash kernels now seem to work with the ghost array, except for HP mobius.
Updated allocation for the ghost array so that malloc/free are not called and textures are not created/destroyed when ghost_bytes = 0