Don't enable compiler debugging information by default.
From Gentoo. Upstream commit message:
This patch fix the availablity of __chk_fail function.
patch from blueness@gentoo.org
Use $PATH when executing chroot command.

The chroot test has been modified to use $PATH when looking for 'chroot',
as its location may differ between systems.
testtree.sh will fall back to looking for a particular binary in $PATH
if it does not exist in the hard-coded location.
Merge pull request #2 from kensington/master

Misc fixes