Add two views, one to handle subscription to a meeting and the other to handle the connection to a meeting.

MeetingsView still usefull to list meetings which are really on the bigbluebutton server. It may be usefull to allow deleting meeting.
Add URLs for the new views.
Add template for the MeetingSubscriptionView.

Think to remove View from  views names.
Remove things which moved in others templates.
Add template for the MeetingConnectionView.
Add a sample base.html template.
Add statics files to enable bootstrap.
Add a new model, PreRegisteredUser which give more control on who can subscribre to a meeting.

Generate longer ID for meetings. Maybe still too short.
Add a new method to send mail to pre-registered users.
Update readme.
Translate mail in english, i'll make french  translations later.
Update gitignore.
Add a date time field to meeting model.
Add the meeting's date in the mail content.

i'll implement intermediate pages with theses actions to allow customize the content of the mail.
Add a form needed by admin intermediate page.
Add the template which allow customizing content of mail.
Add logic to customize mail content, not working for now...
Update readme.
Now able to customize the mail content and send it.

Should I notify when there is no user to send the mail ?
This is necessary to tell django which action action was selected to call it after POST form.