Revisit RAPI error codes
Add calls to get aligner name and version
Add dependency to BWA_PATH check when building bwa wrapper
Comments
Call swig with -builtin

Without it I can't get Python exceptions to be thrown from the wrapper.
Wrapper to instantiate and initilialize rapi_opts
Remove rapi_ prefix from wrapper function names
Move rapi.i to pyrapi directory, since it's becoming language-specific