WIP major refactor
Update fennel to 1.3.0

Rename `&` functions / macros to "rle" for now so that 8fl launches
Do not start 8fl by default

Add start stop functions
Make range inclusive, remove range*
Support single numbers in pick
Rename melo to pick
Add samples and slices
Render pattern immediately if not playing
Stop leaking <> expressions in _G._CYCLES
Stop exhausting REPL locals

Use splice_save_locals from newer fennel REPL
Use negative track numbers for fx columns

Allows use of iterators as track "numbers" for things like chords
Make table iterators resumable
Call loadstring correctly

It never throws errors to pcall is wrong
Add step to range, add range*
Improve error reporting