Merge pull request #2 from TravisEvashkevich/master

Updates to be inline with tech from Boxer
Forgot ignore props for IsVisible/Expanded (could be a feature for remembering last save state up to the thing you were working on)
Added FileLastModified to Sound so I can compare when the sound file that is imported was last modded to check against "reImport" last modded time
Should allow me to only reimport if newer (like what UDK does when you reimport things that are already in your packages)

Set up command for Reimport within the MainWinVM
Merge remote-tracking branch 'upstream/master'