Fixed some state issues where event collisions where happening.

Created a way to prune “interval” messages by default (not needed for Logstash events).
Added more types (old-style time and interval, message and severity)
Have 'release version' computation include the git hash only on .dev
versions
Invoke jruby compilation from ruby code, not via jrubyc

This prevents 'java -jar jruby.jar -S jrubyc' from running something
from $PATH which breaks because jruby expects ruby code and rvm provides
a bash script in its place.
Merge pull request #811 from logstash/better-jrubyc-invocation

Invoke jruby compilation from ruby code, not via jrubyc
Merge pull request #810 from logstash/improve-version-label

Have 'release version' computation include the git hash only on .dev
Echo when we're fetching kibana and ua-parser stuff.
Include 'patterns' dir in the tarball (oops)
Merge branch 'master' of https://github.com/logstash/logstash

# By Jordan Sissel
# Via Jordan Sissel (3) and Aaron Mildenstein (1)
* 'master' of https://github.com/logstash/logstash:
  Invoke jruby compilation from ruby code, not via jrubyc
  Have 'release version' computation include the git hash only on .dev versions
Merge pull request #809 from untergeek/master

Fixed some state issues where event collisions where happening.
Add tarball-test target

Like flatjar-test, etc. This runs the test suite from the built tarball
to make sure we haven't broken or forgotten anything during packaging.
Merge pull request #812 from logstash/improve-tarball-stuff

Improve tarball stuff