SynEdit: added string auto-continue mode

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40351 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: added string auto-continue mode

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40352 4005530d-fff6-0310-9dd1-cebe43e6787f