Improve the way to handle an exception if the command used in popen is not
exists by adding try/except when it's necessary.

Align the output.
Update CHANGES.rst
Put to false all the options who break the build

Indeed the fix for the issue #45 reveals thats the build was wrong before. The command jshint doesn't exist on travis so the script was dying without returning an error value.
This point needs to be discussed
Merge pull request #46 from plone/issue_45

Please merge my branch that resolves issue #45, where I changed the way to manage the "SKIP" output and disable all checks who return SKIP or  FAILURE
Explain deprecated-aliases option (closes #47)
Fix utf-8 headers
Update documentation
Fix the import errors by adding a #noqa when the import is necessary by mock