Follow-ups:

jshint configuration:
* remove all predefined globals from the main .jshintrc default global
* add new jshintrc files for subdirectories

Hook:
* fix the commit hook to fail when jshint is absent
* bailout early if we don't have xfail.list
* add a link to the README file if some xfailed files are commited

Makefile:
* add documentation at the top of the Makefile
* fix Makefile for Mac OS X and other BSD system: don't use `xargs -d`
* support VERBOSE=1 when running make hint
* add a link to the README file when "make hint" is failing

General:
* fix the xfail list sorting and generate a current list
* add the README file