CSS: normalize box-shadow in pre blocks.

git-svn-id: https://plugins.svn.wordpress.org/wp-geshi-highlight/trunk@921058 b8457f37-d9ea-0310-8a92-e5e31aec5664
Release 1.2.2 (bump version numbers, add tag 1.2.2).

git-svn-id: https://plugins.svn.wordpress.org/wp-geshi-highlight/trunk@921059 b8457f37-d9ea-0310-8a92-e5e31aec5664