Improve some error messages
Merge branch 'death-march' of github.com:bipy/qcli into death-march
Cleaned up more error messages and fixed file headers.
Merge branch 'death-march' of github.com:bipy/qcli into death-march

Conflicts:
	qcli/core/command.py
Merge pull request #70 from jrrideout/death-march

Cleanup: code, file header/copyright/license, and error messages