filesystem bindings

[naturallymitchell]

improvements to filesystem bindings, from lighttouch's fs workarounds and gut's fs workarounds

• rm -r
• touch
• join
• symlink
• current working directory
• remove_file
• move_file
• move_dir
• add copy directory excluding .git binding #283

[naturallymitchell]

read file
...?

[Arnaz87]

read file is in the lua standard io library

it's not crazy to have them separated, some languages have separate libraries for io (read/write file content) and filesystem (directories and metadata), rust being one

[naturallymitchell]

append to start of file (prepend)
copy

[naturallymitchell]

open