Start adding a cmdliner interface to the cli ('vhdtool')

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: implement 'check' subcommand

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: add support for streaming disk contents in English

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Add missing file

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: add subcommand 'get' to query individual metadata fields

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: add all the footer fields

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: add 'info' subcommand to display all known fields

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
cli: expose all the header fields

Signed-off-by: David Scott <dave.scott@eu.citrix.com>