Removed partial fix for ECL bug
http://permalink.gmane.org/gmane.lisp.bordeaux-threads.devel/212
as it only slightly postponed the known error
    Condition of type: BORDEAUX-MP-CONDITION
    There is no support for this method on this implementation.

The correct solution is to upgrade ECL to a version released on
19 Jun 2013 or later (git commit 914ce253d1d9e52df684dfacc554167b3f100ce7 or
later).

A temporary workaround is to quit ECL, remove all cached FASL files
from ~/.cache/common-lisp/ecl-*, start a new ECL and finally load STMX and its
dependencies with (ql:quickload "stmx")