Risk streams fix, API change

• Fix: do not risk streams when it is not allowed
• Fix benign warning in Huffman encoder on 32-bit machine
• API: get properties of encoder header block when it ends
• interop-encode: add -f option to encode "f"ast

Fast Huffman Encoder

• Optimize Fast Huffman Encoder: use large table
• Add ability to build library without large tables

QPACK Internet Draft 10 is supported

No functional changes since 0.9.14 -- bumping the version to indicate compliance.

Fix minor bug in Huffman decoder

v0.9.14

Update version to 0.9.14

Huffman encoder and decoder improvements

Synched latest changes from ls-hpack.

Handle invalid header block size; small fixes

Decoder: return error (not crash) if header block is too short

The header block must be at least two bytes long: that is the
length of Header Block Prefix which is always present.

Optimize Huffman decoder

v0.9.10

Update version to 0.9.10

API: enable dup instructions by default

[API] Enable DUP instructions by default

Not using DUP instructions makes compression worse in vast majority
of cases.

API Change, optimizations

v0.9.8

Update version to 0.9.8

API Change, optimizations

v0.9.5

Add a few boundary checking unit tests