SmartMath Plugin - Real-time Calculations in AkelPad

[DV]

Latest changes:
- correcting `sin`, `cos`, `tan` to return exactly 0 where appropriate;
- fixed: invalid user-defined functions did not report an error;
- corrections for `NaN` in comparisons;
- optimizing comparison and bitwise operators (identifying operators by numeric Id instead of string);
- correcting: `int`, `ceil` etc. reject `Inf` and `NaN` arguments;
- new: `rad` and `deg` as a trailing command, similarly to `hex`;
- some code cleanup in "SmartMath.bas".

Still TODO:
- reduce blinking while the calculation results are displayed.
(Actually, it is possible to reduce the number of repaint operations - but, in that case, the calculation results look worse, as if several paint operations are superimposed on one another. This does not look clean and sharp).