Improve infoPanel: 
Register panels based on metadata presence
Limit exif data to images
Use modifier to add a dynamic infoPanel for Share data

Improve Login Box:
Add texture to overlay, prevent box from closing until user is correctly logged.

git-svn-id: https://ajaxplorer.svn.sourceforge.net/svnroot/ajaxplorer/trunk@3410 3bf36de4-da32-0410-8312-848cfbfe3f7d