add ruby 1.9.2p330
Merge pull request #3012 from hone/ruby-1.9.2-p330

add ruby 1.9.2p330
remove the security-head note from config/known
do not check known rubies when patch is missing for 2.1.0, fix #2990, fix #3002, closes #3010
export -f rvm_debug, fix #2978