Plugin folder location

Can't use installation directory: e.g. in windows it would require
running Korsakow as admin.

Use APPData on windows, Application Support on OSX and ~/.korsakow
otherwise.
64-bit build support
Bundle JRE on windows build.
OSX ant build more multiuser friendly.

Signing is optional, requiring an ENV var to perform.
Split launch target into "Build" and "Publish".
Multiuser build path

Eclipse build path references an execution environment instead of a
user-specific JRE
Ant uses java.home

Cleaned up launch configs
Build doesn't create a zip for osx.

Fixed OSX build launch configs.
Merge pull request #39 from dreisch/build_fixes

Build fixes