Initial attempt at using PDO for the underling database connections; duplicated code removed from database_library_sqlite.php which now just contains a setup routine
port the autodetection of site_url from the sqlite-fixes branch into this branch
fix initial sqlite data (management.php username/password are now preset to admin/admin and should work)
Merge branch 'palepurple-mysql-sqlite-pdo' into develop
Fix type in manual
Add Czech run-time language
Some improvements on ldap support

- This needs further testing, and a new section in the manual
Add support for MathJax
Typo in comment
Fix for LDAP

- Needs further testing
Improve user management in back-end
Merge branch 'develop' of https://github.com/thexerteproject/xerteonlinetoolkits into develop

Conflicts:
	website_code/php/database_library_sqlite.php