Make hook functions public
Various changes (breaks existing setups)

- Use same setup as other MediaWiki extensions
-- Config is done with $wg* variables, which are reset in the main PHP
file
-- Hooks are set in the main PHP file
- Use ENUMs to set behaviour of extension ($wgSamlRequirement)
- Added option to load SimpleSamlPhp earlier, so that it can read the
session before MediaWiki changes it
- In setups where no local logons are allowed, change the links in the
header to link directly to SimpleSamlPhp instead of requiring a redirect
- Fixed regression: e-mail will be confirmed again
- Removed unnecessary redirect code
- Small bug fixes
Don't link to secure site when Wiki is not secure
Updated README with new configuration

Rewritten most parts of the README file
Better login/logout URLs

Logout works exactly like stock MediaWiki logout, by setting the
redirect to the original URL.
Merge branch 'master' of github.com:yorn/mwSimpleSamlAuth

Conflicts:
	SimpleSamlAuth.i18n.php