Updated release version.

Set version to 0.2.1.

Updated manifest to include requirements.

Updated setup.py to load requirements from requirements.txt

Updated version for next major release.

Updated version number for the 0.0.5 release.

Updated version for 0.0.4 release.

Terminal now handles KeyboardInterrupt and EOF from ctrl c and ctrl d

to end chat bot sessions.

This also fixes an issue where chatbot would reply after the exit()
command was issued. In addition the exit() command has been marked
for deprication in favor of using KeyboardInterrupt and EOF commands.

Updated history documentation.

Updated documentation.