handling peer disconnect and remote io error during filetransfer

git-svn-id: svn://localhost/project_picapica/trunk@316 fb96df88-216d-11de-830c-f3023f12d8ac
added FileTransferController and FileTransferDialog source files to Makefile.am

git-svn-id: svn://localhost/project_picapica/trunk@317 fb96df88-216d-11de-830c-f3023f12d8ac