Always use g_fopen() and g_stat() instead of fopen() and stat() to fix several problems with filenames containing special characters on Windows. Use GetFullPathName() instead of lrealpath() to get Tagmanager working on files containing special characters on Windows.

git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@1714 ea778897-0a13-0410-b9d1-a72fbfd435f5