workaround static physfs static linking on linux

We need this to fix hedgehog numbers desync (workarounded in previous revision)

and now compile and link properly

Fix stupid mistake which made checker desync almost always

update cmake files to use the two libraries independently

Found another possible source of desync, trying similar workaround on this

split extras and src

Forbit guest checkers

use standard library prefix

Workaround hGetContents blocking all threads with my own version of the function

reopen and update branch

Workaround desync issue if I correctly understand its roots (barely tested)

fix compiling on osx when you have multiple linkers installed

Some fixes

pretty sure esc here is just a holdover from past, and has no use in rearranged implementation.