add a FIXME for the bug in net.sourceforge.fullsync.buffer.BlockBuffer.storeBytes
small WelcomeScreen cleanup, added Preferences.{set,get}SkipWelcomeScreen
update SWT to 4.4M3-201310302000 because of SWT#407077

https://bugs.eclipse.org/bugs/show_bug.cgi?id=407077
added tool to extract SWT releases
About Dialog: simplify accessing the FullSync version number
cleanup .gitignore
only show the WelcomeScreen once for every FullSync version (aka on the first launch after an update)
added a link to the Twitter account to the Help menu
fix language code of the Greek translation (gr => el)
AboutDialog: add my sourceforge address as clickable link
AboutDialog: added twitter link
move the website url into a file instead of hardcoding it at various places
small cleanups
SystamTray: add icon to the open FullSync action