Implement bitmap loading for faces on Haiku

Implement bitmap loading for faces on Haiku

Stipples don't completely work yet.

* lisp/faces.el (face-valid-attribute-values): Enable `:stipple'
on Haiku.
* src/haiku_draw_support.cc (BView_DrawBitmap)
(BView_DrawBitmapWithEraseOp, BView_DrawMask): Don't push and
pop states.
(BView_DrawBitmapTiled): New function.

* src/haiku_support.cc (BBitmap_import_mono_bits): Delete
function.
* src/haiku_support.h: Update prototypes.
* src/haikuterm.c (get_string_resource): Fix coding style.
(haiku_get_bitmap, haiku_draw_stipple_background): Implement
partially.
(haiku_set_scroll_bar_default_width)
(haiku_set_scroll_bar_default_height, haiku_scroll_bar_create)
(haiku_set_horizontal_scroll_bar, haiku_set_vertical_scroll_bar)
(haiku_create_terminal, haiku_scroll_bar_remove): Fix coding
style.

* src/image.c (image_create_bitmap_from_data)
(image_create_bitmap_from_file): Implement on Haiku.