XD-176: Add exponential moving average support.

RichGauge now optionally supports as an alternative to the simple mean.
If the "alpha" smoothing constant is set for the gauge instance it will
calculate an exponential moving average instead.

The "mean" property of RichGauge has been renamed to "average" to
reflect this.
XD-176: Update toString method of RichGauge

Added the "alpha" value.
XD-230 adding rabbit source module
Merge pull request #70 from markfisher/XD-230

* XD-230:
  XD-230 adding rabbit source module
Exclude Spring 3.1 dependencies in spring-xd-test

Prevents occasional clashes running container
and admin in the IDE
XD-231: Twitter "gardenhose" support.

Initial commit - ported from kodiak with some minor alterations.
XD-160 Publish Golo-themed HTML doc to Artifactory
XD-231: Don't retry gardenhose on a 401

If authentication fails, the source fails to start rather than
trying repeatedly.
XD-231: Add back-off support for errors.

Back-off for rate limiting and other errors as required by the
twitter API docs.
XD-231: Add read timeout property to gardenhose.

Prevents the stream hanging in some cases. Default timeout is set
to 90s as recommended by twitter.

See https://dev.twitter.com/docs/streaming-apis/connecting#Stalls
Make log4j a compile sep for spring-xd-dirt

DefaultContainer references log4j classes directly. Needed for Intellij
gradle import.
Add additional links to README.md
Merge branch 'gardenhose'
XD-268: Some cleanup in options management

Fix local banner display

Actual XD-262: Converted existing code to Spring MVC. Needs Content-Type: text/plain to work as before though, will update doc accordingly if merged

Removing unused argument.

Added copyright headers to new files
Simple test infrastructure, testing http codes atm
Fixing merge conflict that went unnoticed
Fix build file formatting
Undo commit of log4j config
XD-144: Leave log4j.properties out of jar files

Added exclude to gradle jar task.
XD-294 Apply JavaDoc HotFix; Fix JavaDocs

Apply hotfix plugin; remove javadoc warnings.