Fix size and text alignment of HildonBanner

Fix size and text alignment of HildonBanner

* hildon/hildon-banner.c
(hildon_banner_class_init):
Center text.
(+hildon_banner_size_request):
Request always the full width of the screen.
(hildon_banner_realize)
(-hildon_banner_check_position, hildon_banner_map):
hildon_banner_check_position() is not needed in Hildon 2.2.
(-hildon_banner_reset_wrap_state)
(hildon_banner_constructor, hildon_banner_init):
Remove unnecessary calls to hildon_banner_reset_wrap_state()
(+banner_do_set_text)
(force_to_wrap_truncated):
Remove has_been_wrapped and has_been_truncated attributes.
(+reshow_banner, hildon_banner_real_show_information)
(hildon_banner_show_information_with_markup)
(hildon_banner_show_animation, hildon_banner_show_progress)
(hildon_banner_set_text, hildon_banner_set_markup):
Refactor code. Shrink banner vertically to use the minimum space
necessary everytime the text of the label is updated.
(screen_size_changed):
Call force_to_wrap_truncated() when the size of the screen
changes.

Fixes: NB#120500 (only device memory connect mmc in use info
banner is left aligned)

Fixes: NB#120613 (Size of HildonBanner varies depending on
previously opened banners)