Add three more small test cases.

1.  When you don't fully type a title and hit enter in the search box you
search for it rather than go to that page.
2.  When you type a namespace prefixed page into the search box it is
found and hitting enter works like any other page.
3.  Categories transcluded into pages from templates can be searched.

Test case 3 is related to Bug 18861.

Change-Id: I2426e1a3ec2fbbb156a38959d4cdc7da1af75974
Merge "Add three more small test cases."