- fix the handling of alpha values passed to set_fill_fg_color() and set_fill_bg_color(). A value of 255 means fully opaque whereas a value of 0 means fully transparent.
- fix the solid fill color import, to use the foreground color instead of the background color.
- xlsx
- import colors to disgonal borders.
- remove carriage returns from multi-line cell strings.
- xls-xml
- import border colors.
- import hidden row and column flags.
Signed-off-by: Pierre-Yves <pyu@riseup.net>