1. Defines ROOT_VERILATOR in vversion, and used to peek into Verilator's
   structures.

2. Defined the size of the inputs to the butterfly, when set to zero.

Comment blocks were added to the tops of the generated twiddle hex files
In fftstage.v
	The idle register was fixed so that it is no longer 'x
	when ZERO_ON_IDLE is clear.
Use of VIM folding was greatly expanded
Tabbing was adjusted, so that statements following an always matched
	the tabbing of the always.
assert-else-assert bugs were found and fixed
Local declarations were grouped together
Verilator lint checks when -DFORMAL is enabled were (partially) fixed
FFT generator's INVALID PARAMETER errors were expanded with better
	explanations of what the underlying error actually was.