This is a minor change where typos and English grammatical mistakes are

Hello,

Thanks for creating django-inspectional-registration, I'm guessing your not a native English speaker and this pull request should fix some minor issues and misspellings and some grammar mistakes in the source files. I haven't looked at the docs and may do update them in a different pull request.

I was changing the words used in the admin as my users mentioned that some of the wording was a little unusual. While I was doing so, I thought I may as well update all of the files. I hope you find this useful and agree with my changes and rewording of some of the text.

Regards
Mick