Merge pull request #140 from arielf/master

Paul Mineiro's hypersearch for general usage + enhancements + bug fix
update build to use zlib-1.2.8
Merge branch 'master' of github.com:JohnLangford/vowpal_wabbit
better error handling and user friendly error messages
Fix ExecCmd return inconsistency; ensure we return best loss in edge cases
Merge branch 'master' of git://github.com/JohnLangford/vowpal_wabbit
Add -b option and Brent's Method - not yet ready for prime time; fix edge-case of missing optimum
Add support for -t test-set; fix @$cmd vs $cmd bug in ExecCmd