Custom proc allocation

- Sketch
Cleaning
Custom processor routing

- Sketch new Signal in/out representation
Cleaning
.gitignore
Cleaning
Add more signal primops
Implemented Signal.isConstant
Add generic append/dappend
Sketch flisp
Sketch flisp
Sketch flisp
Sketch flisp
Sketch flisp
Sketch flisp
Sketch flisp
test.flisp
Lisp tests
Make Fa.List implement Semigroup
Allocate more internal buses

- Needed until internal allocation is rewritten