Improve the test driver
Improve the test driver

The tests are moved to a separate data structure, and we can select a
subset of tests to run.

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