Added _ underscore JS lib to otto runtime

Added the _ underscore JS lib to otto runtime to make deep searching of properties in complex JSON documents possible
Added _ underscore JS library to otto runtime

Added _ underscore JS library to otto runtime to make deep search in complex JSON documents possible
Merge pull request #44 from march44/master

Add _ underscore JS lib to otto runtime for sync functions

See http://underscorejs.org for details and docs.