Add dot notation support to lookup() 

This should solve issue #9 it includes both hash and object method abilities and ignores keys with dots that match similar to the mustache.js implementation. 

I apologize for the lack of tests, I'm using this on an older system then it was built for and I'm lacking a few packages and have older versions of others. (It works beautifully btw. Perl 5.8.8 on RHEL 5)