Major changes! I've broken everything! I've fixed everything!

Changes

No more semantic display functions. (write_int, write_char, write_string) just pass any relevant datatype to write(input).
No more HSV color addressing, just simplified down to CRGB. Thanks, dmadison!
clear() now physically sets the displays to blank, instead of just clearing led_states[]. To clear states without showing, use clear(false).
color_on/off() can accept three r,g,b parameters, or one CRGB object. (dmadison)
Lixie no longer uses a mathematic method to push individual digits of a number to the displays. This worked, but horrible floating point nonsense only allowed accurate numbers up to 34,742.
Switched to uint32_t, up from 16-bit unsigned. 4,294,967,295 is the new maximum - I'd be very happy if people were buying 10 Lixies to even show this number. However, this still isn't even enough for a live U.S. Debt Counter. Fucking hell.

Additions

Added get_numdigits() and maxed_out() functions to check if numbers are too large to display on your configuration. (dmadison)