fgen, iir needs 64bit registers

[lneuhaus]

to uniformize and avoid future bugs, we must add a 64bit float register type

[lneuhaus]

Solution: LongRegister
implemented in fgen, not sure that its useful for IQ. Can represent arbitrary length of bits, just like python int

[lneuhaus]

Solved with LongRegister.

Usage:
addr = 0x124
class MyModule(BaseModule):
myverylongregister = LongRegister(addr, bits = 1234)

returns pyton int with 1234 bit representation from 0x124 to subsequent addresses in fpga :)