Update Sizzle: adjusted POS handling; attribute names should be case-insensitive...

diff --git a/src/sizzle b/src/sizzle
index 76e73cf3e99c22de66e014c54b590b04c4bc9837..2dc6fbfc53c01dcccacbdc17cc10766b95ce1bfa 160000 (submodule)
--- a/src/sizzle
+++ b/src/sizzle
@@ -1 +1 @@
-Subproject commit 76e73cf3e99c22de66e014c54b590b04c4bc9837
+Subproject commit 2dc6fbfc53c01dcccacbdc17cc10766b95ce1bfa