Summary: Added BitStreamPutInt() and BitStreamGetInt() which take a stream of chars and can write integers of arbitrary bit sizes to that stream at arbitrary positions. There are also convenience versions of these functions that take std::strings and leveldb::Slices.
Test Plan: make check
Reviewers: sheki, vamsi, dhruba, emayanke
Reviewed By: vamsi
CC: leveldb
Differential Revision: https://reviews.facebook.net/D7071