MFC r316492: bsdgrep(1): Rip out "xmalloc" bits

xmalloc was a debug malloc implementation, but the x{malloc,calloc,free}
functions default to calling the malloc(3) equivalents.

Instead of relying on this malloc shim, we can devise better ways to debug
malloc issues that aren't misleading upon initial inspection. (I.e., using
jemalloc's various built-in debugging capabilities.)

Approved by: emaste (mentor, blanket MFC)

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Update BSD grep to the latest development version. It has some code
backported that was written for the TRE integration project in Google
Summer of Code 2011. This is a temporary solution until the whole
regex library is not replaced so that BSD grep development can continue
and the backported code gets some review and testing. This change only
improves scalability slightly, there is no big performance boost yet
but several minor bugs have been found and fixed.

Approved by: delphij (mentor)
Sposored by: Google Summer of Code 2011
MFC after: 1 week