topwin: don't clear the MODALED flag beyound MODALING

When creating nesting modal windows, exiting the top level modal window will
mark all the remaining window un-modaled. This commit fix the bug and keep
the lower window under modal.
widget: edit: fix the eol handling in set_text
widget: edit: fix the _string_char_width parameter
Change the class type to a function and export to module; Add rotation and zoom for DC buffer; Add more blit for RGB565/ARGB888.
Change the class type to a function and export to module; Add rotation and zoom for DC buffer; Add more blit for RGB565/ARGB888.