Code simplifications

• Modified Mandel.v to use "generate" to instantiate the calculating engines.
• mandel_constants file now uses $clog2 to calculate the bus widths rather than having to enter that manually.
• Minor bug fix for mod_counter.v to properly indicate the final state.

Better/Faster engine

Eliminated a state in Engine.v, and split the calculation across two states, allowing for a much faster clock (increased to 112 MHz from 84 MHz).
This increased the frame-rate from 13.5 fps to 20.5 fps.

12 engines

Releasing a version of the software (and .sof file) with 12 engines instantiated.

Initial release

Fully functional and complete.