add PIString::lineNumber() method

add ""_tr literal to translate string by PITranslator
add pip_tr util, now useless, only can generate *.ts
add qt_support internal lib, now only works with *.ts file
pip_vtt migrate to qt_support

utils/qt_support/ts_file.h

@@ -0,0 +1,45 @@
+/*
+    PIP - Platform Independent Primitives
+    Ivan Pelipenko peri4ko@yandex.ru
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pistring.h"
+
+namespace TSFile {
+
+struct Message {
+	PIString source;
+	PIString translation;
+	PIString type;
+	PIString filename;
+	PIString line;
+	bool obsolete = true;
+};
+
+struct Context {
+	PIMap<PIString, Message> messages;
+	void confirm(const PIString & msg, const PIString & file, int line = -1);
+};
+
+using Content = PIMap<PIString, Context>;
+
+PIString mask(const PIString & in);
+PIString unmask(const PIString & in);
+
+Content read(const PIString & path);
+bool write(const PIString & path, const Content & content, const PIString & lang, bool no_obsolete);
+
+} // namespace TSFile