Merge pull request #40 from dijkstrw/dev

Updated hp6632b.check_error_queue to work with instrument and nosetests
Some formatting for Lakeshore instruments

Moved "channel"-type classes inside parent class
Formatting and moving channel class in for Oxford ITC 503
Formatting and moving in channel class for Yokogawa7651
Formatting I missed in last commit
Fix for picowatt avs47 resistance query
Similar formatting changes as recent commits for picowatt avs47
Similar formatting for srs345
Forgot to update copyright years in last commit