CommandLine: new command line parser

This implementation behaves mostly identical to old parser.
Few observable differences:
- There are no option groups (single group is used for all options)
- Option --stdout is hidden (it has been obsolete for a long time)
- MPD executable name (mpd) is hardcoded for simplicity

src/CommandLine.hxx

@@ -20,15 +20,13 @@
 #ifndef MPD_COMMAND_LINE_HXX
 #define MPD_COMMAND_LINE_HXX
 
-#include <glib.h>
-
 class Error;
 
 struct options {
-	gboolean kill;
-	gboolean daemon;
-	gboolean log_stderr;
-	gboolean verbose;
+	bool kill;
+	bool daemon;
+	bool log_stderr;
+	bool verbose;
 };
 
 bool