Added DWG icons

Big thx to @parski
Adapt gui_debug.html for css placement. Close #687
Serialized php must be stored as bytea in PGSql - close #680
My Account: disabling WebDav pane was disabling Team Pane as well, use a finer XPath.
Fix mailer testing - Missing description on boot.conf plugin
Merge pull request #675 from Ellega/dwg

Added DWG icons
Commit release notes for 5.3.4
Merge remote-tracking branch 'origin/develop' into develop