install: Remove planex-install

planex-install is broken and no longer needed - remove it.

Signed-off-by: Euan Harris <euan.harris@citrix.com>
XenBuilder integration: Update XenBuilder makefile for new planex

Signed-off-by: Euan Harris <euan.harris@citrix.com>
configure, clone: Add --mirrorsite option to use a local mirror

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Fix colours

Signed-off-by: Euan Harris <euan.harris@citrix.com>