Add 'Detect from file' Editor indentation pref.
Show TAB or SP for current document's indent type.
Minor editing of Document menu and editor Indentation prefs group.
Use GString for statusbar statistics.


git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@1953 ea778897-0a13-0410-b9d1-a72fbfd435f5