Fixed the hard-coded height in HildonPickerDialog

Fixed the hard-coded height in HildonPickerDialog

* hildon/hildon-touch-selector.[ch]
(hildon_touch_selector_optimal_size_request): function added to get a
optimal size request from the touch selector, when you want a dialog to
show as much of the selector
* hildon/hildon-picker-dialog.c:
Removed HILDON_TOUCH_SELECTOR_HEIGHT macro
(hildon_app_menu_class_init):
New "max-height-landscape" and "max-height-portrait" style properties
(hildon_picker_dialog_size_request): redefined GtkWidget::size_request
(hildon_picker_dialog_get_max_height): returns the maximum height using
the style properties defined and checking the current portrait/landscape
status
(_hildon_picker_dialog_set_selector): removed the set_size_request

Fixes: NB#109369 (Hard-coded height in HildonPickerDialog)