Add support for RHEL7

Add support for RHEL7 which uses dconf instead of gconftool-2.

Reviewed by: Swapna Krishnan <skrishna@redhat.com>
Merge branch 'update_rv_connect_rhel7_timeout' of https://github.com/swapnakrishnan2k/tp-qemu into update_rv_connect_rhel7_timeout
spice tests: Increase timeout for rhel7 support in rv_connect

Reviewed by: Swapna Krishnan <skrishna@redhat.com>