Add STR Register support
Add STRH Register support
Add STRB Register support
Update EOR Register tests.

Make sure that each state of APSR_C is explicitly tested.
Updates to STR and STRH Register tests

Added tests which attempt to store to an invalid address to make sure
that a hard fault is returned when the memory subsystem throw a
busErrorException.
Small refactoring to improve code coverage
Add LDRSB Register support
Add LDR Register support
Corrected instruction name in comment.