add incremental compilation

add incremental compilation + improve snooping

* fix snooping

* fix precompile file

* fixes to compile more

* rename

* fix remaining issues

* do the snoopy thingy

* add cleaner incremental solution

* escape correctly

* don't rebuild for snooping

* fix typo

* fix broadcast

* work with non toml packages

* clean up snoop + incremental - fix bugs

* fix some more bugs:

* add docstrings

* add the packages we need to manifest

* add tests

* better tests + fixes for tests

* remove failing tests

* remove more

* fix tests

* fix tests

* correctly include pgk compiler

* fix windows bugs

* no success

* Update src/incremental.jl

Co-Authored-By: SimonDanisch <sdanisch@gmail.com>

* Apply suggestions from code review

Co-Authored-By: SimonDanisch <sdanisch@gmail.com>

* cosmetics

* correctly implement run_julia

* fix flags

* fix tags + add multi package compile

* use correct flags

* use package toml

* parse test REQUIRE even if toml is present

* allow snoop file to error

* fix atexit

* use sysimgfolder idiomatically

* also add packages from toml

* fix bug + easier reuse