Log message:
sysutils: Remove SHA1 hashes for distfiles

Log message:
Update xenkernel415 and xentools415 to 4.15.1.
32bits PV guests are now unsupported security-wise, and upstream disables
them by default. This packages keep the support enabled for transition, but
this will change for the next quarter branch. It is recommended to switch to
pvh+pvshim for PV guests (or pvh if you run netbsd-current).
Other changes are bugfixes, including fixes for XSA up to XSA-384

Log message:
*: Remove PKGREVISION=0

Log message:
Add xenkernel415 and xentools415 version 4.15.0

Xen is a hypervisor which supports running multiple guest operating
systems on a single machine. Guest OSes (also called "domains")
can be either paravirtualised (i.e. make hypercalls in order to
access hardware), run in HVM (Hardware Virtualisation Mode) where
they will be presented with virtual devices, or a combination where
they use hypercalls to access hardware but manage memory themselves.
At boot, the xen kernel is loaded along with the guest kernel for
the first domain (called domain0). domain0 has privileges to access
the physical hardware (PCI and ISA devices), administrate other
domains and provide virtual devices (disks and network) to other
domains.