mkdir init
add to makefile, basic mkdir functionality done
remove cat warning, update makefile
Fix test for cat, add mkdir test
Update readme, add success message at end of tests
move parent opt check, update tests
merge cat/test.rs
remove unneeded typing, swap cat and mkdir
update test dir paths into tmp dir
Fix base64 due to from_utf8 and replace changes

These two changes were made in rust's std lib:
    1. `str::replace` was a method of str, now it's a function.
    2. `from_utf8` now wraps its return value in Option.
rm: make InteractiveMode derive Eq
Merge pull request #74 from Arcterus/rm

rm: make InteractiveMode derive Eq
Merge pull request #70 from jordyd/base64

Fix base64 due to from_utf8 and replace changes
Merge pull request #55 from juszczakn/master

Implemented mkdir
mkdir: update for latest Rust

I'm doing this from my phone, but I assume that it's okay to do this directly seeing as I merged mkdir because it was easy to fix.
dirname fix according from_utf8 return option now
fix wc due from_utf8 changes and resolve warnings
basename: use fail instead of writeln to stderr
update cat for current Rust syntax with ugly errors handling
replace writing to stderr with fail