make_mo.py: stop if msgfmt command is not available.

Set x-bit for tools extract_pot.py and make_mo.py.

tools/make_mo.py

@@ -154,7 +154,10 @@ def process_po_folder(domain, folder):
         # Create the MO file
         mo_file = os.path.join(mo_path, mo_name)
         print 'Compile %s' % mo_file
-        os.system('%s -o %s %s' % (TOOL, mo_file, fname))
+        ret = os.system('%s -o %s %s' % (TOOL, mo_file, fname))
+        if ret != 0:
+            print '\nMissing %s. Please install this package first.' % TOOL
+            exit(1)
 
 
 def make_templates():