add documentation about command line arguments

text is auto generated from the arguments help text

ref. #166
updates 2.6 requirements to fix issue #174.

 simplejson > 2.1
Merge branch 'feature/Document-the-command-line-options' of git://github.com/saxix/cookiecutter into saxix-feature/Document-the-command-line-options
Merge branch 'saxix-feature/Document-the-command-line-options'
Add troubleshooting info about Python 3.3 tests and Tox.
Merge branch 'feature/issue-174' of git://github.com/saxix/cookiecutter into saxix-feature/issue-174
Merge branch 'saxix-feature/issue-174'
Merge branch 'master' of https://github.com/audreyr/cookiecutter