Fixes utc_blink_ewk_view_orientation_send_func unittest

Fixes utc_blink_ewk_view_orientation_send_func unittest

In order to fix utc_blink_ewk_view_orientation_send, we need to use the
new screen orientation API instead of window orientation.

Also, an orientation of -90 is transformed into a 270 orientation
by ewk. So, we need to take that into account

In addition, in order to make the test more thorough, we add a test to
check that an invalid orientation value isn't propagated.

Lastly, we remove the files orientation_test1.html,
orientation_test2.html and orientation_test3.html which were unused.

Bug: http://107.108.218.239/bugzilla/show_bug.cgi?id=6980

Reviewed by: a1.gomes, djmix.kim

Change-Id: Iae76f08151a753272877d9839c3660842f0b161b
Signed-off-by: Arnaud Renevier <a.renevier@samsung.com>