Added the custom icons and added the code to display the custom icons to the screen
based on the category of the saved bird sighting.

Signed-off-by: maroon5five <randy_miller@mail.com>

	new file:   res/drawable-hdpi/bird_map_icon.png
	new file:   res/drawable-hdpi/misc_map_icon.png
	new file:   res/drawable-hdpi/nest_map_icon.png
	modified:   src/com/catalyst/android/birdapp/MapActivity.java
	modified:   src/com/catalyst/android/birdapp/database/DatabaseHandler.java