Move subsurface-core to core and qt-mobile to mobile-widgets

Having subsurface-core as a directory name really messes with
autocomplete and is obviously redundant. Simmilarly, qt-mobile caused an
autocomplete conflict and also was inconsistent with the desktop-widget
name for the directory containing the "other" UI.

And while cleaning up the resulting change in the path name for include
files, I decided to clean up those even more to make them consistent
overall.

This could have been handled in more commits, but since this requires a
make clean before the build, it seemed more sensible to do it all in one.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

core/gettextfromc.cpp

@@ -0,0 +1,27 @@
+#include <QCoreApplication>
+#include <QString>
+#include "gettextfromc.h"
+
+const char *gettextFromC::trGettext(const char *text)
+{
+	QByteArray &result = translationCache[QByteArray(text)];
+	if (result.isEmpty())
+		result = translationCache[QByteArray(text)] = trUtf8(text).toUtf8();
+	return result.constData();
+}
+
+void gettextFromC::reset(void)
+{
+	translationCache.clear();
+}
+
+gettextFromC *gettextFromC::instance()
+{
+	static QScopedPointer<gettextFromC> self(new gettextFromC());
+	return self.data();
+}
+
+extern "C" const char *trGettext(const char *text)
+{
+	return gettextFromC::instance()->trGettext(text);
+}