Export the underlying allocation from a waiting structure
Export the underlying allocation from a waiting structure

...so that all kind of diagnostic tasks can be carried out without
duplicating the functionality on the waiting structure. Note that
we still do not export the constructor so that we can change the
implementation without breaking the interface.

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

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