Add a command to gnt-debug to test various aspects of wconfd
Add a command to gnt-debug to test various aspects of wconfd

For debugging purpose, support direct communication to WConfD from
the commandline for some of its commands. For the time being, support
the echo command.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>

ganeti/ganeti,ganeti/ganeti,onponomarev/ganeti,onponomarev/ganeti,yiannist/ganeti,bitemyapp/ganeti,grnet/snf-ganeti,mbakke/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,andir/ganeti,andir/ganeti,yiannist/ganeti,apyrgio/ganeti,andir/ganeti,ganeti/ganeti,leshchevds/ganeti,dimara/ganeti,dimara/ganeti,grnet/snf-ganeti,mbakke/ganeti,leshchevds/ganeti,yiannist/ganeti,leshchevds/ganeti,apyrgio/ganeti,ganeti-github-testing/ganeti-test-1,bitemyapp/ganeti