Update Condor scripts to use new CondorProduction package

A lot of the Condor functionality developed here in the TreeMaker repo (counting jobs, managing jobs, finding missing jobs, etc.) is useful for more general purposes. That functionality has now been moved into its own package, CondorProduction.

The Condor workflows in TreeMaker (ntuple creation, counting neff) have been converted to use this package. This simplifies the amount of code to be maintained in TreeMaker, and standardizes/improves some existing functionality.

CondorProduction is still a new effort, so some bugs may be encountered. The adapted workflows have undergone basic tests at this time.

Also, the installation instructions are converted to a setup script for easier use.