Updated Readme
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.
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.