Instead of the incomplete heuristic parenthesis expansion,
now expressions with Logo functions and with own
procedures are parsed completely, solving several issues
with complex Logo expressions. For example, now functions with
more than 1 argument don't need explicit parenthesization.

NOTE: to handle both Logo and Python syntaxes of function calls,
we differentiate the forms "f(x)" and "f (x)". The second form
is handled as Logo syntax, not the Python one:

f x*2 y z     -> f(x*2, y, z)
f(x*2, x, z)  -> f(x*2, y, z)
f (x*2) y z   -> f((x*2), y, z)

so if you want to avoid of the following expansion:

sin 45 + cos 45   -> sin(45 + cos(45))

it's possible to use the following parenthesizations:

sin(45) + cos 45  -> sin(45) + cos(45)
(sin 45) + cos 45 -> (sin(45)) + cos(45)

but not

sin (45) + cos 45 -> sin((45) + cos(45))

Change-Id: Ib0602b47b8b678a352313f471599d44d6904ce17
Reviewed-on: https://gerrit.libreoffice.org/62901
Tested-by: Jenkins
Reviewed-by: László Németh <nemeth@numbertext.org>