fix build on OpenBSD

- expose a new flag (--system-boost) to
  build ycmd with system boost.
- don't link against librt on OpenBSD
- add "-pthread" to CXX flags on OpenBSD
Merge pull request #54 from Mischi/fix-build-on-openbsd

fix build on OpenBSD
Minor code formatting
Updating to latest Jedi
Test for FilenameCompleter with unicode filename
Ensuring /event_notification always returns JSON

Empty string is not valid JSON.

Fixes #51.
JediCompleter basic test
Fixed Python docstrings with unicode chars

Was throwing a UnicodeEncodeError.

Fixes #1257
Minor code formatting
Treating -iframework and -F as include flags

Fixes Valloric/YouCompleteMe#1233
build: fix `python_finder`: prefer python2, look for/prefer .so

This fixes building YCM / ycmd for pyenv with python3 and python2
activated/configured.
Merge branch 'fix-build-python-config'

Conflicts:
	third_party/jedi