Support "mvim" script symlinks to [m|g]ex, rmvim

Symlinks to "mex" or "gex" starts MacVim in ex mode.  Symlinks to "ex"
starts Vim in ex mode (no GUI).  Symlinks to "rmvim" (or "rgvim" which
was already supported previous to this patch) starts MacVim in
restricted mode.

src/MacVim/mvim

@@ -39,12 +39,12 @@ gui=
 opts=
 
 # GUI mode, implies forking
-case "$name" in m*|g*|rg*) gui=true ;; esac
+case "$name" in m*|g*|rm*|rg*) gui=true ;; esac
 
 # Restricted mode
 case "$name" in r*) opts="$opts -Z";; esac
 
-# vimdiff and view
+# vimdiff, view, and ex mode
 case "$name" in
 	*vimdiff)
 		opts="$opts -dO"
@@ -52,6 +52,9 @@ case "$name" in
 	*view)
 		opts="$opts -R"
 		;;
+	*ex)
+		opts="$opts -e"
+		;;
 esac
 
 # Last step:  fire up vim.