Slight change to the LU initialization code
Slight change to the LU initialization code

This patch adds support for a separate LU.CheckArguments() method which
should do syntactic checks without holding locks and without polluting
the ExpandNames which is a lock-related function. See for example the
FIXME in LUSetInstanceParams.CheckPrereq.

The patch also removes the REQ_MASTER and IsCluster checks since with
the current architecture, inside LU code we are always in a valid
cluster and we are always running on the master node.

Reviewed-by: ultrotter

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