Various fixes and improvements

Small release to do fix some minor bugs and to improve the data.

• add ability to have notes on fixtures (#25)
• add ability to have a postcode on venues (#26)
• add ability to have directions for venues (#27)
• add a mandatory trigram for teams (#28)
• removed the ability to register directly on the site (#14)

The Interactive Fixture Loading process has also been improved:

• the Add button, that was greyed-out, has now been removed. Implementing it present challenged that I am not prepare to face yet (#30)
• the Map button has been rename correct_to, and repositioned to make it easier to understand what it is for (#31)