Integration with new askuser UI apps

Integration with new askuser UI apps

This patch adds implementation of ppm_popup_send_response API
as well as new implementation of requesting a popup, using
askuser-popup external application.

Internally the patch removes m_currentEvent usage, allowing
the popups to be processed, theoretically, in parallel
for many requests.

Patch does not:
* add security check to ppm_popup_send_response
* remove not-needed EFL code

Above things will be done in separate patches.

Change-Id: Iaeb1d797141b750b462d21bd619e92e0c647e235