mtlb_colordef Matlab colordef emulation function

## Description

There is no Scilab equivalent function for Matlab `colordef` but there are equivalent instructions.

The function `h = mtlb_colordef(color_option)` or `h = mtlb_colordef(fig,color_option)` is used by `mfile2sci` to replace `colordef(color_option)` or `colordef(fig,color_option)` when it was not possible to know what were the inputs while porting Matlab code to Scilab. This function will determine the correct semantic at run time. If you want to have a more efficient code it is possible to replace `mtlb_colordef` calls:

- When called with one input parameter, if `color_option` is equal to "black" or "none" `mtlb_colordef(color_option)` may be replaced by `fig = gcf();fig.background = -1;`

- When called with one input parameter, if `color_option` is equal to "white" `mtlb_colordef(color_option)` may be replaced by `fig = gcf();fig.background = -2;`

- When called with two input parameters, if `fig` is a graphic handle and `color_option` is equal to "black" or "none" `mtlb_colordef(color_option)` may be replaced by `fig.background = -1;`

- When called with two input parameters, if `fig` is a graphic handle and `color_option` is equal to "white" `mtlb_colordef(color_option)` may be replaced by `fig.background = -2;`

- When called with two input parameters, if `fig` is equal to "new" and `color_option` is equal to "black" or "none" `mtlb_colordef(color_option)` may be replaced by `fig = scf(max(winsid())+1);fig.background = -1;`

- When called with two input parameters, if `fig` is equal to "new" and `color_option` is equal to "white" `mtlb_colordef(color_option)` may be replaced by `fig = scf(max(winsid())+1);fig.background = -2;`

- When called with one output parameter `h`, just add `h = fig;` after equivalent instructions.

Caution: `mtlb_colordef` has not to be used for hand coded functions.

## See also

- figure_properties