- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r265255, r270506:
Allow "a.out" as an alias for the executable if no other matching entries
are found.

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

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

- Compute the correct size to reallocate when doubling the size of the
array of loaded objects to avoid a buffer overrun.
- Use reallocf() to avoid leaking memory if the realloc() fails.

PR: kern/175648
Submitted by: yuri@rawbw.com (1)
MFC after: 1 week

Several fixes for libproc:
o return the correct status in proc_wstatus()
o proc_read takes a void *
o correctly allocate the objs structure array

Sponsored by: The FreeBSD Foundation

New version of libproc. Changes are:
* breakpoint setup support
* register query
* symbol to address mapping and vice-versa
* more misc utility functions based on their Solaris counterpart

Also, I've written some test cases.

Sponsored by: The FreeBSD Foundation