Use sizeof() instead of strlen() for tag names known at compile time

git-svn-id: http://forge.voodooprojects.org/svn/chameleon@2338 b5af796a-00a8-11df-919b-ffff7a100b7d
Defend against buffer overruns in FlattenNodes

git-svn-id: http://forge.voodooprojects.org/svn/chameleon@2339 b5af796a-00a8-11df-919b-ffff7a100b7d