Merge pull request #22 from stephanenicolas/skip

This is a combination of 3 commits.

* 14ecde245f9ca579e6515da9c73fa1b6e9bca5f0 - Prefix properties. Add
skip. Issue #13
* a17cab81b8cd32cf1bd1d3bc62e4276d97b98ff5 - Enhance documentation
* 49974d5b7aba1f006db22f6fc74051ec88835dba - show that skip can be
omitted.