VMware Infrastructure Perl Toolkit Code

First checkin of reference / utility applications built using the ViPerl toolkit.

Applications provide host and vm information and operations.

Fix issue of sessionfile or (username, password) absense
not being handled as an invalid command option.

This fix ensures the absense of these args is handled as
a parameter validation error, and usage is printed out as a result.

Verified that --help and --version work as expected with these options absent.

Experimental support for selectively filtering views.

Added a new 'properties' argument to the view commands get_view(s) and
find_entity_view(s). The argument is a list of property paths to be
retrieved from the server. These can be full paths and are not
restricted to top-level managed properties. For example, to populate a
virtual machine view with just the power state information, you can
write:

my $vm_view = Vim::find_entity_view(view_type => 'VirtualMachine',
filter => { 'name' => 'foo' },
properties => [
'runtime.powerState' ]);

To retrieve properties from a filtered view, you should use the new
get_property method of the view. For example:

my $state = $vm_view->get_property('runtime.powerState');

Note that you can also get subproperties of the retrieved property:

my $vm_view = Vim::find_entity_view(view_type => 'VirtualMachine',
filter => { 'name' => 'foo' },
properties => [ 'config.hardware' ]);
my $memsize = $vm_view->get_property('config.hardware.memoryMB');

And that get_property works with fully-populated views as well. So:

my $vm_view = Vim::find_entity_view(view_type => 'VirtualMachine',
filter => { 'name' => 'foo' });
my $memsize = $vm_view->get_property('config.hardware.memoryMB');

Is equivalent to:

my $vm_view = Vim::find_entity_view(view_type => 'VirtualMachine',
filter => { 'name' => 'foo' });
my $memsize = $vm_view->config->hardware->memoryMB;

When using a filtered view, any attempts to read a property that wasn't
retrieved from the server will act the same as if the property were
unset.

The use of property filters is intended primarily as a performance
optimization to reduce the latency and network bandwidth of retrieving
full views of a large number of objects. In general, you should start
with full views and only switch to filtered views when tuning
application performance.

Note also that this support is currently experimental and may change or
be removed in the future.

This implements solution where PrimType
type is used to denote types of primitives for serialization. Because primitives types are
essentially 'untyped' in Perl, we need a way to detect whether a singular is string, boolean, short, long , etc. There may be ways to make this easier
on users but it will likely require a lot of engineering effort to make it happen (guess based on specific API calls maybe?) and after looking at
this solution, it doesn't look so terrible to me. I've added a bonus sample that uses this new type for scheduled task creation

Updated reference in README to correct filename for alpha User's Guide.

Renaming the alpha documentation so that it includes the word 'alpha' in its name, to avoid any confusion when subsequent updates occur.

Add a missing SelectionSpec to the computeResourceRpTraversalSpec in get_search_filter_spec.

Add support for setting and querying version information.

The VI Perl version is defined as the $VERSION of VIRuntime.pm. A
VILib-enabled script can specify its own version number by setting the
$Util::script_version variable. Calling a script with --version will
print the version of VI Perl itself, along with the script if
specified.

Added two new samples:
guestvars.pl - Script to inspect and modify Guest Variables
removabledevices.pl - Script to list, connect, and disconnect removable virtual devices

Added a new function to the VILib Util package:
get_inventory_path - return the inventory path for an entity (view). The inventory path can later be passed to the FindByInventoryPath operation to retrieve the ManagedObjectReference for the entity.

Reverting the documentation to the alpha version. Too many issues to consider at this point to try to upgrade the external documentation prior to the release.