reorganization:
	all .cs files moved to .src
	stats.cs divided in multiple files (under src/stats)
	sqlite.cs divided in multiple files (under src/sqlite)
	somewindows.cs divided in multiple files (under src/gui)
	Makefile changed
	added this changelog.txt

stats changes:
	gui improved (4 statsJumpsType modes)
	simplesesion and multisession with fewer code in each stat
	in simplesession we can show lots of columns, in multisession one per session
	weight in sj+ cmj+ and abk+ is all converted to percent or Kgs depending on preferences
	changes in sqlite: cleaned lot of stats code

others:
	added DB version in sqlite (for managing updates of database in the future)
	obligation of name for new session and new person
	obligation of weight for all jumpers, then we can show all the values in stats as '%' or as 'Kg' by simple conversion
	minor changes