Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Remove unneeded headers.

MFC after: 1 month

Prefer <stdint.h> over <sys/types.h>. While here remove redundant
inclusion of <sys/queue.h>.

Move the inclusion of the disk partitioning headers out of order
and inbetween standard headers and local header. They will change
in a subsequent commit.

Avoid depending on the <sys/endian.h> header for le*enc and be*enc.
Not only is the header unportable, the encoding/decoding functions
are as well. Instead, duplicate the handful of small inlines we
need into a private header called endian.h.

Aside: an alternative approach is to move the encoding/decoding
functions to a separate system header. While the header is still
nonportable, such an approach would make it possible to re-use the
definitions by playing games with include paths. This may be the
preferred approach if more (build) utilities need this. This
change does not preclude that. In fact, it makes it easier.

Add VHD support to mkimg(1). VHD is used by Xen and Microsoft's Hyper-V
among others.

Add an undocumented option for unit testing (-y). When given, the image
will have UUIDs and timestamps synthesized in a way that gives identical
results across runs. As such, UUIDs stop being unique, globally or
otherwise.

VHD support requested by: gjb@

MFuser/marcel/mkimg:
Add support for different output formats:
1. The output file that was previously written is now called the raw format.
2. Add the vmdk output format to create VMDK images.

When the format is not given, the raw output format is assumed.