Add new parallel test for zero accesses

 - tests reading/writing with size=0
Add new parallel test for zero accesses

 - tests reading/writing with size=0
Rebased against dev branch (trigger test)
Merge branch 'zero-access' of github.com:ComputationalRadiationPhysics/libSplash into zero-access

Conflicts:
	tests/Parallel_ZeroAccessTest.cpp
Merge pull request #83 from ComputationalRadiationPhysics/zero-access

Add new parallel test for zero accesses