if preference is not set, show SearchFavoriteFragment; if it is set, show ResturantListFragment directly.
get the search filter from the preference and apply the query term to yelp api.
Merge branch 'master' into use_preference

Conflicts:
	Foodie/src/com/yahoo/foodie/activities/SearchFavoriteActivity.java
move the new friend methods from SearchFavoriteActivity to RestaurantListActivity as the former is deprecated now.
cleanup and bug fix.
Merge pull request #30 from Zhongtang/use_preference

Use preference