Update README to reflect release.
Merge pull request #212 from jozic/sbt-0.12

Set correct development version for scripted tests
Allow overriding default sbt-idea settings.
Add test for #211
Add correct managed source directories to Idea config (#209)

As per http://www.scala-sbt.org/release/docs/Howto/generatefiles.html, managed
sources should be generated into plugin specific subdirectory of a 'sourceManaged' setting. 
Previously 'sourceManaged' directory itself was added to Idea configuration.
Merge pull request #207 from christophercurrie/patch-1

Update README to reflect release.
Set language level according to scala version used by the module (#195)
Add compiler plugin continuation to project settings
Changed implementation acording to Mikko Peltonen guides in the comment on the pull request.
(https://github.com/mpeltonen/sbt-idea/pull/203#issuecomment-13190607)

Extracted the scalacOptions mapping to a map and added translation of "-explanintypes", "-optimise" and "-nowarn".

The defined mappings will no longer be inclueded in the compiler options tag as idea don't do this.

All paths with -Xplugin: will be include in the plugin path list
Use the xplugin val to generate pluginPaths thanks to Eugene Platonov for pointing that out.
Add test for #203
Minor code cleanups
Merge branch 'issues/203' into sbt-0.12
Evaluate 'managed-sources' task if project has source generators

This is needed to have all generated source folders created and available in 
Idea metadata.
More optimistic log message
Use relative instead of absolute paths
Fix path relativization issue
Add notes for 1.4.0
Set version 1.4.0
Set next development version