bugfix: exception when no checkboxes are selected

genericAssertion: new argument type 'array0'. Useful for array of checkboxes
createTriplet: use array0 genericAssertion
saveQuickLinks: No more exception when no checkboxes are selected
doVSMigrate: idem
make tag name regexp easy to maintain

lexError1: format most popular non-printable chars into escape sequences
getLexemsFromRawText:
	- count lines in single place, process character before counting a line
	- FSM change. Every character except \n is correct when collecting a name.
	  After collecting, the entire name is validated with validTagName

TAGNAME_REGEXP, AUTOTAGNAME_REGEXP, validTagName moved into functions.php
TAGNAME_REGEXP weakened a bit