Add "String to SymTerm" parser based on Parsec
Implement derivation
Add parser for Ln
Parser: Ignore whitespace
Beta: evalTermP evaluates a term containing Variables

Using an association list
Added abs() clause
Merge branches 'pu/parse', 'pu/eval', 'pu/simplify' and 'pu/derivate' into next

Test release
Moved fromMb to Symmath.Util
Prototype of a simple function value table function
Beta: Function value table.

TODO:
    - Align the table as Perl would do it with its formats.
    - Allow rounding to more or less decimals than 3
Merge branches 'master', 'pu/funtable' and 'pu/simplify' into next