Python tools

This is a collection of Python tools that have been developed for the GLAMS project, and I'd like to move to the main repo. I'll remove the Draft prefix once I'm sure it's been integrated into Truchas correctly. This:

• Fixes our Python probe reader to work with the new text-based probe output.
• Adds the ability to generate Truchas input files from a template and a dictionary of variables.
• Adds 1D parameter study tooling. Take a variable and a list of values for that variable, generate all the input files, run Truchas on each, store some user-provided metrics to a table in a text file. There's also a pair of functions here for simply generating the inputs--which might be farmed out to a SLURM array job--then registering existing output data to a database (below).
• Adds a tool for caching Truchas outputs in a database. This is useful when doing a collection of parameter studies on different variables. If a certain input file has already been executed, you can read data from the cached output instead of rerunning Truchas.