Fix out-of-tree build for python
HPACK post -05 updates

* Use 1 Huffman code table for both request and response
* Remove complicated deflater side table size management
* Add encoding context update
* Fix memory leak in inflater
Fix inflater memory leak
Out-of-tree build for sphinx documents

The only drawback is that page source only contains include
directive. We disabled page source for now.
Update .gitignore
Merge branch 'master' into draft-10