tests: fix leak on aggregate test.
stream-buffer: always pass null buffer for buffer initialization.
buffer: fix references to new buffer init.
buffer: ensure realloc size includes current offset and length.
build: bump libbson for next_power_of_two().
tests: make check will auto recurse.
reply doesn't seem to be required so let's not init it if it is not set
Merge pull request #49 from fotonauts/mongoc_bulk_operation_execute_without_reply

reply doesn't seem to be required so let's not call bson_init() if it is not set
Merge branch 'tengen-master'

Conflicts:
	src/libbson
	src/mongoc/mongoc-buffer.c