TS-2207: CentOS5 out of tree perl module build fails

The older version of automake on CentOS5 doesn't supply the $(builddir)
variable, possibly because it's implicitly the current working
directory. It also doesn't supply various $abs_ variables that later
versions do. Rewrite the copy using more fundamental automake
variables.

Conflicts:
	CHANGES
TS-2207: stop using $(builddir) in automake

Older automake (< 1.9?) doesn't emit $(builddir), but it's always
"." anyway, so let's use that instead.
TS-2144 Avoid race on e.g. -Cclear which would crash the process
Added TS-2144.