added setFlags method in Id combo box. Removed possibility to send anonymous distant messages (too risky). Improved the logic in message composer GUI. Fixed bug when key not available in message encryption/signing routine.

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7705 b45a01b8-16f6-495d-af2f-9b41ad6348cc