s3put: accept headers values containing "="

s3put tries to split headers on the "=" sign. Some headers include a "=" sign (e.g. max-age), and can't be used. 

This pull request splits on the first equal sign to support those.

Caveat: if a user uses the command correctly (`s3put --header "header1=value1 header2=value2"), they won't get an exception.
Added tests for poll() tasklist override fix.
Adding fix for poll() task_list override bug in actors.
Adding test for standard poll() behavior with no task_list override.
Merge pull request #1700 from krallin/s3put-fix-header

s3put: accept headers values containing "=". Fixes #1700.
Fixes #1713 - Corrected a DDB bug where scanning over large set with a filter may not return all results.
Bumped Cloudsearch to SigV4.
Bumping version to v2.13.1
Merge branch 'release-v2.13.1' into develop

* release-v2.13.1:
  Bumping version to v2.13.1
Corrected erroneous test failures in Cloudsearch post-move to SigV4.
Finalized the release notes.

Mynd you, møøse bites Kan be pretty nasti...
Bumping version to v2.13.2
Merge branch 'release-v2.13.2' into develop

* release-v2.13.2:
  Bumping version to v2.13.2
Packaging makes me :cry:.
Bumping version to 2.13.3
Merge branch 'release-2.13.3' into develop

* release-2.13.3:
  Bumping version to 2.13.3
Spruced up doc fails.
Add a --region argument to s3put that allows you to manually specify a region, and use boto.s3.connect_to_region to simplify creation of the connection object.
Fixes #1729 - Removed erroneous ``dry_run=`` parameter.
Merge remote-tracking branch 'oozie/fix_swf_poll_tasklist' into develop
Fixes #1724.