Fix warnings in ewk/efl_webview_app/mini_browser.c

Fix warnings in ewk/efl_webview_app/mini_browser.c

This patch fix 9 warnings in mini_browser.c

> passing argument 1 of 'ewk_context_vibration_client_callbacks_set'
from incompatible pointer type
> passing argument 3 of 'evas_object_smart_callback_add' from
incompatible pointer type
> initialization from incompatible pointer type
> (near initialization for 'values[0].strp')
> assignment from incompatible pointer typen
> unused variable 'permissionRequest' [-Wunused-variable]
> implicit declaration of function 'ewk_start_tracing'
[-Wimplicit-function-declaration]
> implicit declaration of function 'ewk_stop_tracing'
[-Wimplicit-function-declaration]

Bug: http://web.sec.samsung.net/bugzilla/show_bug.cgi?id=15558

Reviewed by: sns.park

Change-Id: Iac5fe427fbde3b2093cce95c4651ac6c8261ee31
Signed-off-by: y0.kim <y0.kim@samsung.com>