- change start() and set_text() to use "format" and "..." instead of
"message", allowing to format progress messages in place
- s/cancelable/cancellable/
- move "cancellable" to be the second argument of start()
In gimp_tool_progress_start(), if the progress is cancelable, grab on
an invisible widget and emit the progress' "cancel" signal when Escape
is pressed.
This removes the obsolete check which makes the tool fail from
gimp_display_shell_set_mask(). Also change the foreground select tool
and the display mask from using GimpChannel to GeglBuffer, because
that's what it needs, simply buffers. Most changed files simply newly
include <gegl.h> because a GeglBuffer appeared in two headers.
