Code contributor:
Volker Dirr (to contact Volker Dirr visit http://www.timetabling.de/)
	Lots of helping with testing, bug reports, suggestions, comparisons

	XHTML generation code modified by Volker Dirr from old HTML generation code
	(old code by Liviu Lalescu)
	added features: - XHTML 1.0 strict valid
		- use colspan and rowspan
		- times vertical
		- table of contents with hyperlinks
		- css and JavaScript support
		- print rooms timetable
		- level of HTML for timetables
		- print groups and years timetable
		- print subjects timetable
		- print teachers' free periods timetable
		- print activities timetable
		- index HTML file
		- print daily timetable
		- print activities with same starting time

	Import and export of CSV files

	Export of advanced statistics

	Important suggestions and partial code for great speed improvements in some particular cases
	(better computation for initial order of activities, which leads to much faster generation for some
	particular cases of timetables).

	Idea and partial code for locking the activities.

	Activity planning dialog.
