Implement an OOP framework around Tincr

[bradselw]

Currently, Tincr's API closely mimics that of Vivado's: methods are formatted like batch commands, with parameters passed in via switches. This is verbose and hard to parse.

Re-format Tincr's API to resemble an OOP language: function signatures should accept parameters without requiring switches. Simulate classes by encapsulating functions inside of Tcl ensembles that operate on individual Vivado objects.