Adds cms 2.4 & 3.x compatibility.
Drops django < 1.4 support.
PEP 8 cleanup.
version bump to 0.4
updates README
Merge branch 'feature/ckeditor' of github.com:czpython/cmsplugin-text-ng into feature/ckeditor
Merge pull request #9 from czpython/feature/ckeditor

Adds cms 2.4 & 3.x compatibility.