Complete rewrite of plugin.
Only base processing functions in place at this time.
Allows for multiple equations and multiple variables per heading.
Support for integer, floating-point and scientific notation.
Complete rewrite of the outline math plugin.
Exampls in votl_math.otl
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
Updates and corrections in the help file
Fixed issue #66.
Note: helptags must also be regenerated.
Removed last remnants of vo- and replaced them with votl-.