Fix for #1451

Line codec was using an undefined variable which casued it to throw and exception.

Fixed and added tests for line codes

Closes #1451
Squash extra lines
Verify method is getting called
Reference github issues now.

Hosted Jira (logstash.jira.com) is currently busted because we have
exceeded the maximum number of users that platform can accomodate
(according to Atlassian support). Until that is resolved, let's point
everyone at github issues instead.

closes #1508
fix connection threads tracking leak

better mutex name, loop with while true

event per connection & thread cleanups specs

remove leftover

closes #1509
logstash boot sequence cleanup & drip support fix
deprecated USE_JRUBY environment var
added USE_RUBY and USE_DRIP environment vars
centralized gem path handling in LogStash::Environment

use consistent discovery strategy
Add tests to cover codec autoswitch for stdin + tcp inputs

json->json_lines & plain->line

Tests for #1392
Closes #1394
inputs/base: Copy the codec's charset when switching.

Includes tests
Merge remote-tracking branch 'upstream/master'