Make Travis CI build faster

Merge Github pull request from PeterDaveHello. This closes #7.
Regenerate charmonizer.c for whitespace fix
Fix RegexTokenizer in C bindings

Add missing charmony.h include. Fixes LUCY-270.
Fix QueryParser regression with underscores in field names

During the StringIterator rewrite, I broke parsing of field names with
underscores. Fixes LUCY-269.

TODO: Add a test case.
Bump Devel::PPPort dependency to version 3.14

Building with PPPort version 3.13 can fail because emulation of mPUSHs
for older Perls was first added in Devel::PPPort 3.13_01.
Update LICENSE

The autotools install script isn't bundled with Lucy anymore.
Generate a Lucy static lib in addition to a DSO.
Regen charmonizer.c (static lib changes).
Optimize and fix encoding of similarity values

The previous code was a bit unclear as it extracted the LSB of the
exponent as part of the mantissa. This did actually work because
exponent and mantissa were stored next to each other like in the IEEE
format. For the same reason, the code can be optimized to use a single
shift and mask operation. The actual encoding does not change.

More importantly, this commit fixes a bug where, due to a missing range
check, values smaller than 2^-31 were encoded as 255 and subsequently
decoded as approximately 2^31. Such small values are probably rare but
this could cause significant errors when calculating similarities.
Optimize decoding of similarity values

Decoding of similarity values can be optimized in a similar way.
Adapt for Charmonizer CLI changes.
Regen charmonizer for CLI changes.
Remove --disable-threads configure option

This option is only used by Clownfish.
Use chaz_CLI for --clownfish-prefix option
Regenerate charmonizer.c
Adjust autogen headers for Clownfish changes