constpp, rave bugfixes

constpp is a new preprocessor introduced alongside asm2bf.
It can be used to alias instruction and register names, like so:

?r6=sp

; and now

sub sp, 4

; is equal to

sub r6, 4

No spaces are allowed after and before =, no spaces are allowed inside aliases, no spaces are allowed after the question mark (?).

Rave has now a 16-bit compatibility option.

Raw left and right bracket fix for Rave (oops)

Now the bitness example has the correct brackets used to create a while loop.

smp and amp micropatch

Removed dependency on -lfl