Adding get_many() and exists_many() API.
Adding comments in a code.
Test cases for get_many() and exists_many() API's.
Adding test cases for get_many()
No need to call as_batch_destroy
Changed error messages.
Adding test cases for exists_many() API.
Made Invoke methods static, as they are not being invoked outside of respective files. Changed exists callback method name.
Policy changes

Conflicts:

	src/include/policy.h
	src/main/policy.c
Pulled mbf branch changes related to Policies.
Validating policy fields.
updating parameters
Memory leak issues resolved. Decrementing ref counts for unused variables.
Handle return value in case of query.foreach, return False will terminate the loop and come out.
Adding test case for query.foreach to stop on false return
Merge branch 'batch'
up version to 1.0.32