Fixed a few issues while using to deploy Eclipse Luna

init.pp defaulted pluginius to [] instead of undef.  This caused the install to immediately fail when it went to try and process plugins.

I added an unless attribute on the exec for chmoding the eclipse directory to stop if from redoing that each time puppet runs. No big issue but cleans up the noise.

init.pp was missing the $ when it compared pluginius to undef.