Ignore all *.out files under tests

This will be the conventional extension for storing the output of any
shell test runs, and so they should never be checked into git
Move arg_parse into it's own file and rename function
Add some readability whitespace
Have Arg_parse.process return the argument count
Refactor Arg_process.process to use a match statement
First try at implementing quoting

Doesn't work, because it doesn't remove the quotes!
Add basic test of quoting
Flesh out testing infrastructure
Quoting is *barely* functional

Needs significant work to be correct though
Add mli file for arg_parse
Remove counter arg, replace with buffer

Which is currently just a pass through
Add type mostly documenting the call signature of split
Implement usage of the string buffer
Use consistent parenthisization
Rewrite find_quote to have less failure
Add some readability whitespace
Simplify and correct end of string case
Add a debugging function
Expand on quotes testing
Improve tests by testing minishell return code