hn1 was deprecated for a while and this patch removes it altogether. The
support code in Cluster.hs is also removed.

This adds two new stats - sum of reserved ram and disk.

This uses the newly-added Node.availDisk to compute the actual available
disk correctl, and display the total allocatable disk in hspace.

This function returns the amount of available disk, which depends on
whether a low disk limit has been configured or not and on the free disk
space of the node.

Currently we track the max disk usage/max vcpus as percentages, however
sometimes it's easier to check against minimum free disk or maximum
number of cpus, as units instead of percentages.

This patch adds two new variables, lo_dsk, hi_cpu, which are recomputed
whenever we change the m_dsk/m_cpu 'master' values.

Currently totalResources returns a 5-tuple of integers. This is not easy
to handle, as each change on the return type means that each caller must
be updated.

This patch adds a new type for cluster stats and uses that instead as
its return type. This simplifies its callers while complicating only a
little the computation of the stats.

The display of cluster resources is extracted into a separate function
and enhanced to display more stats.

This patch changes Cluster.totalResources to compute more details about
the cluster status, and enhances hspace to display more of these.

Currently hscan has a number of bugs:
  - doesn't add the common suffix (csf) to the instance's nodes
  - doesn't export the cpus for neither nodes nor instances
  - doesn't support single-node instances

This patch fixes these issues.

We modify Node.addPri/addSec to take into account the limits on instance
adds.

Two new min disk free ratio and max cpu usage attributes are added to the
nodes. These will be used in the future to restrict allocation.

This removes some unused functions and imports to cleanup the warnings.

In a few places (e.g. tryRead or any printf call) it's a little bit hard
to add the correct type signatures, but in the it is possible to fix
these warnings (which can bite one in subtle cases).

This is just some cleanup of the node list output, adding pcpu/vcpu
counters, and making the display slightly nicer.

The cpu counters are update on primary instance adds/removes.

This patch adds cpu-count related attributes to nodes:
  - total cpus
  - cpus in use
  - ratio of virtual:physical cpus

We also set correctly the cpu values at load time, but we don't do
anything yet while moving instances around. The cpu ratio is shown in
the cluster list.

This patch adds reading of vcpu count for instances, in preparation for
using the vcpu ratio in cluster scoring.

IAllocator currently uses a wrong key name for reading the total disk
space (‘disk_usage’ which was copied from RAPI, but the actual
iallocator key is ‘disk_space_total’).

This patch fixes that and also makes iallocator always use this key,
instead of computing the size by itself—with Ganeti 2.0 this is
key is always available.

Small updates to the documentation and make a new small release.

During a replace-primary instance move, on the real cluster the instance
is temporarily started on the secondary, and as such we must check that
the secondary node can hold it for this duration. Currently the code
does not, and depending on cluster scoring it will put instances on such
'bad' secondaries (usually without enough memory).

This patch fixes this by adding/removing the instance as a primary on
the secondary node; and then using the result node as the new secondary.
(Since we're in a monad, we could have just tried the allocation and
dropped the result, but this is more clear).

This also fixes other required node numbers.

Currently tryAlloc/tryReloc do not return the new instance, as this is
not needed for IAllocator alloc/reloc requests. However, for computing
the space, the new instance is useful, so we modify these functions to
return this information too.

The patch also improves hspace to have (with default parameters) a
parseable output.

This is a tool that checks how many instances (of same size, specified
by command line arguments) can be added to a cluster while remaining N+1
compliant.

And an alignment issue.

This patch makes sure that all references to the name of the software is
ganeti-htools, not simply htools.

This doc-patch adds copyright and license information to (hopefully) all
needed files.

This patch moves the test declaration into QC.hs, so that test.hs has to
be modified only when we add a new test category.

These are generic enough to be used from multiple places, they belong
better in Cluster.hs than in the hail source.