Reformed the macros OSRF_METHOD_VERIFY_CONTEXT and _OSRF_METHOD_VERIFY_CONTEXT.

Reformed the macros OSRF_METHOD_VERIFY_CONTEXT and _OSRF_METHOD_VERIFY_CONTEXT.

1. Renamed _OSRF_METHOD_VERIFY_CONTEXT to OSRF_METHOD_VERIFY_CONTEXT_
and the variable __j to _j, to avoid using reserved identifiers.

2. Applied the do/while(0) trick to accommodate multiple statements.

3. Avoid evaluating the macro arguments more than once.

4. Rearranged the white space for readability.

This update is a Band-aid.  These macros should turn into a proper function.

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1618 9efc2488-bf62-4759-914b-345cdb29e865