Wrote test class for SearchElementRetriever and clean the test class for
PlantDataRetriever
Modified BookmarkManager and BookmarkManagerTest.
Removed all the set methods for News.
Changed parameter of toggleBookmark to Int and parameter of
deleteBookmarks to List<Integer> and make necessary changes to
BookmarkManagerTest
search page and search result page modified
delete images
Merge remote-tracking branch 'origin/data'

Conflicts:
	floraSG/src/com/example/florasg/BookmarkManagerTest.java
	floraSG/src/com/example/florasg/Model/News.java
Merge branch 'master' of https://github.com/ironlulu/FloraSG

Conflicts:
	floraSG/src/com/example/florasg/BookmarkManagerTest.java
	floraSG/src/com/example/florasg/Model/News.java