rhqapi: add support for readin callTimes from resource

this is kind of special thing. When a resource has metric of dataType
CALLTIME (it's capable to collect response time) we're injecing
getCallTimes() method to that resource object.
rhqapi: support for enabling strict mode within query

This can be done by passing special key parameter _opts (for now it
supports strict mode only) _opts:{"strict":true}
rhqapi: gracefully fail when creating criteria object and user passes
wrong type of parameter value
added tests for RT filter

this verifies that RT filter is correctly pre-configured on RHQ Server,
tests enable RT metric on coregui and rest depoyments, do some hits and
validate response times are reported correctly (technically it checks count
of hits)