CLOUDSTACK-3491 delete host resulting NPE; Exception caught while handling disconnect: java.lang.NullPointerException

Changes:
- During host deletion, host entry in databse gets removed prior to the disconnect task getting processed.
- This causes the disconnect task to get NPE while trying to do the host state transition
CLOUDSTACK-3821 RegisterTemplate URL validation issue

Changes:
- Added validation for the url path
CLOUDSTACK-3820: UI > Infrastructure menu > zone detail > UCS > associatesUcsProfileToBlade API has been changed from sync to async. Here is related UI change.
Bring back vm_data.sh which deleted by a KVM related commit

The following commit removed vm_data.sh, but the file shared by Xen as well.

Bring the file back.

commit 28855b4987c9274d15a539b9d7ae26c0073b0651
Author: Marcus Sorensen <marcus@betterservers.com>
Date:   Wed Jul 24 13:58:17 2013 -0600

    Summary: Get away from dozens of ssh/scp calls for KVM vm_data push

    Detail: userdata and vm metadata take a long time to program on KVM routers.
    This does it all in one go, processed on the router.

    BUG-ID: CLOUDSTACK-3163
    Tested-by: Wido
    Signed-off-by: Marcus Sorensen <marcus@betterservers.com> 1374695897 -0600
CLOUDSTACK-2536: fix the regression introduced by 4c81ea69c4e8326cc81a0e2607f6a6d99645ce5f
DB upgrade: added db upgrade paths for CloudPlatform (Citrix) releases 303,304,305,306,307 to 4.2
CLOUDSTACK-3232: InternalLB system vm - allocate control ip address from the private range when vm's hypervisor is vmWare
CLOUDSTACK-3820: UI > Infrastructure menu > zone detail > UCS > blade - remove blade detailView since it's not used.