Use MSWin environment variables USERPROFILE and APPDATA.

Instead of GRAMPSHOME. GRAMPSHOME is based on the assumption that
the config directory is GRAMPSHOME/gramps, and that causes the
default location for reports and backups to be ~/Library/Application Support.
The MSWin variables allow the two to be separated.

Thanks to Tim Lyons for the suggestion.

mac/gramps.launcher

@@ -39,7 +39,8 @@ export PYTHONHOME="$bundle_res"
 export GRAMPSDIR="$bundle_lib/python$PYVER/site-packages/gramps"
 export GRAMPSI18N="$bundle_data"/locale
 export GRAMPS_RESOURCES="$bundle_data"
-export GRAMPSHOME="$HOME/Library/Application Support"
+export USERPROFILE="$HOME"
+export APPDATA="$HOME/Library/Application Support"
 
 # Strip out the argument added by the OS.
 if /bin/expr "x$1" : '^x-psn_' > /dev/null; then