Added syntax conceal for math equations. Concealed equations appear as µ.
Modified math and result processing to maths can come either before or
after the variables:
	Heading {3*5} result=15
	Heading restult = 45 {9*10/2}
Command Review:
	,,mm	quick recalculate this heading and parents
	,,mt	recalculate children of this node, then the parents
	,,md	recalculate the whole document
	,,mh	hide equations in a µ conceal
	,,mH	unhide equations