Minor corrections

At login checks if user was logged out before saying 'you are logged
out' and corrected misspelled 'href'
Stop user from leaving with unsaved changes, edited Terms

Fixes #25 using window.onbeforeunload at friends.php
Work on #9 Added 'Termination' paragraph at terms
Update README.md

Added 'Want to contribute?' and 'Want to use it?'
Merge 'semantic' part 1

For pull request #26