Version bump on versions/0.5 branch after 0.5.0 release (i.e. in
anticipation of v0.5.1).
Add support for 'missing' as a match key to support ordering on
missing match values, and fix a bug w.r.t. lowercasing match variable
names.
Remove error-causing slashes from the match_regex sample config.
Add 'txt' to code-block declaration, since leaving it off causes the text
to not be rendered.
Escape backslashes so they render as desired.
Merge pull request #738 from mozilla-services/no-regex-slashes

Remove error-causing slashes from the match_regex sample config.
Avoid an extra call to parse when the entire buffer is consumed.

The buffer offsets were reset but the the needData flag was not.
This causes an extra call to parse, the first to set the flag and
then next to read more data an attempt a parse.
Merge pull request #745 from mozilla-services/stream_parser

Avoid an extra call to parse when the entire buffer is consumed.
Config directory support.
Add note re: regex tester.
Merge pull request #748 from mozilla-services/doc-regex-tester

Add note re: regex tester.
Merge pull request #747 from mozilla-services/logstreamer-dir-config

Config directory support.
Skip the obvious irrelevant files when loading heka config dir. Not a
complete solution to #750, but deals with the biggest pain point.
Merge pull request #751 from mozilla-services/exclude-config-files

Skip the obvious irrelevant files when loading heka config dir. Not a
Changelog update.
Release prep.
Merge tag 'v0.5.1'
Pull in a new lua_sandbox to fix JSON encoding of empty strings
Merge pull request #754 from mozilla-services/sandbox_json_serialization

Pull in a new lua_sandbox to fix JSON encoding of empty strings
Fix the max_hosts check to properly reclaim expired hosts when at capacity