Revert "Merge pull request #15 from mantacode/add_command_shell"

This reverts commit d026ae73d5b6d6c466b98b6ff7cd5138088daa07, reversing
changes made to f4356bcee04204a62cc4feffb1c67e1ebba65877.

Multiple blocking bugs found. If we want to pick this back up
later we can re-branch from the reverted commit and rebase from
current master.