HALO: new drawables for hdpi and mdpi

- scaled down the xhdpi drawables properly for hdpi and mdpi
- removed some old and unused halo pngs

Conflicts:
	packages/SystemUI/res/drawable-hdpi/halo_back_left.png
	packages/SystemUI/res/drawable-hdpi/halo_back_right.png
	packages/SystemUI/res/drawable-hdpi/halo_bg.png
	packages/SystemUI/res/drawable-hdpi/halo_bigred.png
	packages/SystemUI/res/drawable-hdpi/halo_black_x.png
	packages/SystemUI/res/drawable-hdpi/halo_dismiss.png
	packages/SystemUI/res/drawable-hdpi/halo_marker_b.png
	packages/SystemUI/res/drawable-hdpi/halo_marker_l.png
	packages/SystemUI/res/drawable-hdpi/halo_marker_r.png
	packages/SystemUI/res/drawable-hdpi/halo_marker_t.png
	packages/SystemUI/res/drawable-hdpi/halo_pulse1.png
	packages/SystemUI/res/drawable-hdpi/halo_x.png
	packages/SystemUI/res/drawable-hdpi/ic_launcher_clear_active_holo.png
	packages/SystemUI/res/drawable-hdpi/ic_launcher_clear_normal_holo.png
	packages/SystemUI/res/drawable-hdpi/ic_notify_halo_normal.png
	packages/SystemUI/res/drawable-hdpi/ic_notify_halo_pressed.png