added comment, the OTL Extension mechanism should not be here

git-svn-id: svn://svn.code.sf.net/p/fonttools/code/trunk@546 4cde692c-a291-49d1-8350-778aa11640f8

Lib/fontTools/ttx.py

@@ -181,6 +181,8 @@ def ttCompile(input, output, options):
 	try:
 		ttf.save(output)
 	except OTLOffsetOverflowError, e:
+		# XXX This shouldn't be here at all, it should be as close to the
+		# OTL code as possible.
 		overflowRecord = e.value
 		print "Attempting to fix OTLOffsetOverflowError", e
 		lastItem = overflowRecord