Added linked list import
added iterator import
Added Abstract Method
Merge branch 'part3' into part4

Conflicts:
	src/com/anderscore/simpleandroidchat/ChatActivity.java
	src/com/anderscore/simpleandroidchat/ContactListActivity.java
	src/com/anderscore/simpleandroidchat/MessengerService.java
added adapter init todo
initialized adapter and set to list
Merge branch 'part3' into part4
little fix
Merge branch 'part1' into part2
Merge branch 'part2' into part3

Conflicts:
	src/com/anderscore/simpleandroidchat/ContactListActivity.java
Merge branch 'part3' into part4