Custom handlers' db moved to user space.

Custom handlers' db moved to user space.

[Issue#] N/A
[Problem] N/A
[Cause] N/A
[Solution] Custom handlers' db moved to user space.
[SCMRequest] N/A

[Verification]
1. Build and install repository
2. Delete old db (rm /usr/dbspace/.wrt_custom_handlers*)
3. Apply commit to wrt-extra http://slp-info.sec.samsung.net/gerrit/#/c/184465/
4. Install and run widget manual_tests/wrt_test_widgets/custom_handlers/custom_handlers.wgt
5. Register handlers for content and scheme (inside widget)
6. Open db /opt/usr/dbspace/.wrt_custom_handlers and check if new records apeared in tables.

Change-Id: I07ce20f03846c3b82fff300810ac9ade99131cee