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.h

@@ -0,0 +1,18 @@
+#ifndef GETTEXTFROMC_H
+#define GETTEXTFROMC_H
+
+#include <QHash>
+#include <QCoreApplication>
+
+extern "C" const char *trGettext(const char *text);
+
+class gettextFromC {
+	Q_DECLARE_TR_FUNCTIONS(gettextFromC)
+public:
+	static gettextFromC *instance();
+	const char *trGettext(const char *text);
+	void reset(void);
+	QHash<QByteArray, QByteArray> translationCache;
+};
+
+#endif // GETTEXTFROMC_H