Backport v3.0 customer class
* Use Bootstrap Buttons
* Remove jQuery UI usage
added alertBox class for messageBox output
make compatible with bootstrap alert messages

Conflicts:
	includes/classes/message_stack.php
Rename tep_ to osc_
Move the registered session_write_close shutdown function call to after other core classes have been initialized to allow other/earlier registered shutdown functions access to the session data
* Backport v3.0 MessageStack class
* Force use of addError(), addWarning(), addSuccess(), and addInfo() class methods instead of add()
Remove redundant file
Move payment error message to the messageStack
Remove redundant definitions