Adding Open and Save As dialogs

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/gsoc2013qt@33395 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6
Changes to open files in the background

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/gsoc2013qt@33409 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6