First commit, much to do, bed time
Made the method by which commands are executed much cleaner. Much less duplicate code. Also set up recursive method for piped commands. Not yet tested. Currently implemented: cd, echo, pwd, ls.
added ps command
Added wc function
Added diff function
Added the history command
Changed the way in which commands are parsed and executed
added grep, tidied up a few bugs and finally got pipes working
Fixed bug in way pipe validity is checked
Removed a heap of un-needed functions, can now run a process in the background, added a few tests
fixed bug in interpret, piped commands can now be run in the background
Merge pull request #1 from hbateman/feature/Alpha

Feature/alpha