Improves examples. Closes 332.

Removes unnecessary removals from E.4.2, E.4.3, E.5.2, E.5.3.
Add pseudo-code for integer decoding. Closes 293.
Adds possibility to update maximum table size.

Closes #341.
Change Huffman tables usage.

Same Huffman table for requests and responses.
Specific Huffman table for cookies.
Merge branch 'master' of https://github.com/http2/http2-spec