Dutch Localization updated

Added the "Syncing" = "Syncing"; line to every Localizable.strings
file, Updated dutch localization translated the helpfiles, fixed links
in help files, Changed the Command-? description to reflect what it
actually does, checked alignments in nib files and adjusted where
neccesary.
Merge pull request #159 from Konstruktionist/Dutch-localization

Dutch Localization updated