Promote geoip and useragent filters to milestone 3

These filters both have tests and have been around for a while. GOOD JOB
FILTERS!
Merge 1.4.0 beta + rc changelog into 1.4.0 changelog
Merge pull request #1178 from jordansissel/prep-1.4.0-GA

Prepare 1.4.0 GA
Fix default value handling
Sometimes ua_version.major and ua_version.minor are nil
Merge remote-tracking branch 'upstream/master'
Merge pull request #1181 from jordansissel/bugfixes

Bugfixes
Retry errors writing to Elasticsearch

Stud::Buffer's flush invocation automatically retries (forever) any
failures to flush.

Supersedes #1180
Merge pull request #1182 from jordansissel/retry-on-failure

Retry errors writing to Elasticsearch
Update changelog
Update to use 'subject' so tests don't conflict with eachother
Restore patch from #1144 that was somehow lost.
Remove unused docs
Remove unused docs
Use 'make package' for building rpms/debs for contrib
Dont need 'build time' in the iteration
Release/upgrade notes for 1.4.0
Add link to release notes and changelog
Version bump
Version bump