Bug 993037 (part 1) - http/2 draft 11 client implementation. r=mcmanus
Bug 993937 (part 2) - Update unit tests for http2 draft11. r=mcmanus

This updates our copy of node-http2 to the version that implements
draft11, and has the one-line change to make the xpcshell test work.
Bug 1001022 part 1 - http/2 draft 12 client implementation. r=mcmanus
Bug 1001022 (part 2) - Update unit tests for http2 draft12. r=mcmanus
Bug 1003320 - Send HPACK buffer size updates when receiving SETTINGS_HEADER_TABLE_SIZE. r=mcmanus