Terriko/cynara geolocation

This patch inserts cynara checks for the geolocation privilege into the browser process on Tizen.  This is necessary to ensure that the geolocation API is available only to webapps that have explicitly asked for this privilege on Tizen, since geolocation is one of the five privileges mediated by the browser rather than the extension process on Tizen.

There will be two other sets of changes related to this one in order to provide complete protection.
1. Modifications to the installer to register permissions needed with cynara https://github.com/crosswalk-project/crosswalk/pull/2518
2. Modifications to ensure that the Extension Process and Render Process are run with appropriate per-app SMACK labels.  https://github.com/crosswalk-project/crosswalk/pull/2397/

This patch obsoletes BUG=XWALK-2092 and is part of the solution to XWALK-553

Notes:
- This needs more extensive testing with a geolocation-capable device, but I don't have one available to me.

[edit: removing things that have been resolved in latest commit]

@pozdnyakov 
Your usage of Cynara API is very wrong. Arguments 2, 3, 4 and 5 for `cynara_check()` should be different:
- **client** should be the application identifier, not a fixed string. On Tizen, for Smack and Cynara policy, applications are identified by their Smack label. Ideally you should get the Smack label of requesting render process from socket fd used to communicate with RP. Consider using `cynara_creds_socket_get_client()` from cynara-creds-socket.h.
- **client_session** this one is tricky. In current static Cynara policy it doesn't make much difference, I suggest using an empty string for now. We will revisit this parameter in the future.
- **user** this should be a textual representation of user id requesting for permission. If we are 100% sure, that BP and RP will always run with the same UID on Tizen (as it is right now), it should be enough to get current UID in BP and convert it to string. Still it would be safer to explicitly get the UID from remote, RP side. You might use `cynara_creds_socket_get_user()` over the sock fd to get it.
- **privilege** should be a proper Tizen name for the privilege. According to https://wiki.tizen.org/wiki/Security:Tizen_3.0_Core_Privileges, the proper name for geolocation is *http://tizen.org/privilege/location*.