- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

per style(9):
Kernel include files (i.e. sys/*.h) come first; normally, include
<sys/types.h> OR <sys/param.h>, but not both. <sys/types.h> includes
<sys/cdefs.h>, and it is okay to depend on that.

Add some USB gadget example drivers for USB audio, USB keyboard,
USB mouse and USB modem classes. Hopefully someone will find
these examples useful when implementing USB device side drivers
using the FreeBSD USB stack.