Accept prebuilt Query object in connection.query

This allows support code to construct a Query instance to be used with
a connection made available in the future.
Fix undefined variable error
export Query constructor
Factor Query creation into an exported function.
Merge pull request #358 from grncdr/patch-1

Accept prebuilt Query object in connection.query
Added missing var, stop mocha from complaining on tz
Merge pull request #365 from silentrob/master

Mocha was complaining on leaking variable
Merged master with pool
Added pool documentation
Merge branch 'pool' of github.com:felixge/node-mysql into pool