transfer status in FileTransferDialog

git-svn-id: svn://localhost/project_picapica/trunk@310 fb96df88-216d-11de-830c-f3023f12d8ac
disable Pause button until transfer is started

git-svn-id: svn://localhost/project_picapica/trunk@311 fb96df88-216d-11de-830c-f3023f12d8ac
pause/resume of file transfer now works

git-svn-id: svn://localhost/project_picapica/trunk@312 fb96df88-216d-11de-830c-f3023f12d8ac
added file_finished() callback

git-svn-id: svn://localhost/project_picapica/trunk@313 fb96df88-216d-11de-830c-f3023f12d8ac
fixed pause/resume bugs, moved callbacks.file_progress() call for outgoing transfer inside send_file_fragment to make it always be called before finished_callback

git-svn-id: svn://localhost/project_picapica/trunk@314 fb96df88-216d-11de-830c-f3023f12d8ac
implemented file transfer cancellation

git-svn-id: svn://localhost/project_picapica/trunk@315 fb96df88-216d-11de-830c-f3023f12d8ac