Updated runtime files.

Add Serbian translations and spell checking.
diff --git a/src/po/Makefile b/src/po/Makefile
index 89672e3..8c4aaf3 100644
--- a/src/po/Makefile
+++ b/src/po/Makefile
@@ -30,6 +30,7 @@
 		pt_BR \
 		ru \
 		sk \
+		sr \
 		sv \
 		uk \
 		vi \
@@ -72,6 +73,7 @@
 		pt_BR.mo \
 		ru.mo \
 		sk.mo \
+		sr.mo \
 		sv.mo \
 		uk.mo \
 		vi.mo \
@@ -113,6 +115,7 @@
 		pt_BR.ck \
 		ru.ck \
 		sk.ck \
+		sr.ck \
 		sv.ck \
 		uk.ck \
 		vi.ck \