Use SRLs for small sync delays
Added QDR vacc controller HDL
Added pfb mux files
whitespace changes only
Change function name to match filename
Fix catastrophic yank-put error.

Subtractor now actually subtracts, rather than adds :-s
Support non-2^n Antennas.

Adjusted a few counters so they explicly roll over
at the correct values
Fix a couple of bugs

1. Counter was being treated as a width-1 signal in a delay. Fixed this.

2. Allow sample counter to be reset by a sync, as well as maximum value.
This fixes a dodgy first accumulation coming out of the x-engine
Changes to comments
Give buf_sel registers initial values of 0

This stops simulink barfing when attempting to
simulate the xengine and use the buf_sel_out
signal.