fixed cz -> cs language code, added slovak translation stub

cockatrice/cockatrice.pro

@@ -182,8 +182,9 @@ TRANSLATIONS += \
 	translations/cockatrice_fr.ts \
 	translations/cockatrice_ja.ts \
 	translations/cockatrice_ru.ts \
-	translations/cockatrice_cz.ts \
-	translations/cockatrice_pl.ts
+	translations/cockatrice_cs.ts \
+	translations/cockatrice_pl.ts \
+	translations/cockatrice_sk.ts
 
 win32 {
 	RC_FILE = cockatrice.rc

cockatrice/cockatrice.qrc

@@ -46,8 +46,9 @@
 	<file>translations/cockatrice_fr.qm</file>
 	<file>translations/cockatrice_ja.qm</file>
 	<file>translations/cockatrice_ru.qm</file>
-	<file>translations/cockatrice_cz.qm</file>
+	<file>translations/cockatrice_cs.qm</file>
 	<file>translations/cockatrice_pl.qm</file>
+	<file>translations/cockatrice_sk.qm</file>
 
 	<file>resources/countries/at.svg</file>
 	<file>resources/countries/au.svg</file>

cockatrice/src/window_main.cpp

@@ -179,6 +179,7 @@ void MainWindow::actAbout()
 		+ tr("Japanese:") + " Nagase Task<br>"
 		+ tr("Russian:") + " Alexander Davidov<br>"
 		+ tr("Czech:") + " Ondřej Trhoň<br>"
+		+ tr("Slovak:") + " Ganjalf Rendy<br>"
 	));
 }