Added a base shell that is capable of running programs in the /bin directory.
Added a log of what is working and what still needs to be implemented.
Added /usr/bin/ to path
Added /usr/bin/ to path and updated TODO list
Added Username, Host name and current directory to command prompt.
Added changes to prompt to currently implemented and added a new item to TODO.
Implemented built-in function cd.
Added basic redirection template
 Fixes #5. Implemented redirection of stin and stdout for new process.
Fixed bug that was introduced in previous commit.
Made fixes to coding style and documentation.
Can now append redirected output to a file using >>
Made error message in check_redirection() write to stderr.
Initial commit for Issue#7
Included the library to access history features
Put constraints on the names of files that can be created from the redirection of stdout.
Ignores empty input string and reprints prompt.
Merged with redirection branch.
Added history call to the shell
Fixes #7 - Prints the last 10 entered commands