Transition from QtCore to stdc++ / STL / boost

This looks like a pretty major change, but in reality,
80% of it is just renames of types and corresponding
methods.

The config parsing code has been completely replaced
with a boost::program_options based version. This
means that the config file format slightly changed
(checkout the updated README).

I still expect there to be bugs / unforseen events.
Those should be fixed in follow up commits.

Also, finally reverted back to using pkg-config to
locate and link libruby. Yay for less hacks!

binding-mri/binding-util.h

@@ -22,7 +22,7 @@
 #ifndef BINDING_UTIL_H
 #define BINDING_UTIL_H
 
-#include "./ruby/ruby.h"
+#include <ruby.h>
 
 enum RbException
 {
@@ -134,7 +134,7 @@ int
 rb_get_args(int argc, VALUE *argv, const char *format, ...);
 
 /* Always terminate 'rb_get_args' with this */
-#ifndef QT_NO_DEBUG
+#ifndef NDEBUG
 #  define RB_ARG_END_VAL ((void*) -1)
 #  define RB_ARG_END ,RB_ARG_END_VAL
 #else