Push cms beta version to 3.0b4.dev5

See https://github.com/divio/django-cms/commit/042f4953f6d2db66fd15e4cb748ab4b279f57947
Added docs, improved wording in wizard
Merge pull request #55 from Chive/feature/push-beta-version

Push cms beta version to 3.0b4.dev5
Merge pull request #56 from Chive/feature/docs-new-args

Added docs, improved wording in wizard
Rename to djangocms-installer
Rename executable
Merge pull request #57 from nephila/feature/renaming

Renaming to djangocms-installer
Change name in documentation
Revised changelog