pluginuis should be undefined to avoid if case.

Defaulting pluginuis to the empty array is a problem as the if case
below checks if it is undefined.  When it runs on an empty array, it
fails with an eclipse exception.
Added unless on modeclipse exec to prevent it from always running.
Missed $ on variable reference causing if case to always run
Merge pull request #7 from petehayes/master

Fixed a few issues while using to deploy Eclipse Luna