test/efl: use static_cast for actionslider's smart data

The pragma GCC diagnostic doesn't work properly on gcc >= 4.7.1

Seems to be related to this bug:
 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55881

Thus, we have to avoid the actionslider macros :-/.

Since Elementary 1.7.x uses a different accessor than 1.8+ to get
to the underlying smart data, added a configure check for the
elementary version (HAVE_ELM_1_7) in order to select which accessor
needs to be used.

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>