39612: Question Mark causes Eclipse Graphical Layout Editor to Freak Out

Handle string values starting with ? and @ even if they do not correspond
to actual theme or resource URLs.

Also fix the code which handles processing strings read from XML files;
apply unescaping rules (for unicode, newlines and tabs, removing quotes,
etc).

Also make the style warning include the full resource URI (it was only
logging the stripped URI).

Change-Id: I9b9a87ac4841faeacd1d94a43fa091702e60f4d8
9 files changed