Comments to help MAMP users on OSX

I'm +1 on highlighting the `port` option. Maybe the MAMP MySQL port number could be a little note/sentence added to the tutorial Database Configuration sections.  (http://book.cakephp.org/3.0/en/tutorials-and-examples/blog/blog.html#database-configuration)  (http://book.cakephp.org/3.0/en/quickstart.html#database-configuration).  I'd be careful about how "MAMP" is defined though, because when I first read this I first thought of traditional "native" MAMP, not the independent bundled software thingy.  (The only reason I thought of/knew otherwise was from hearing you talk about it on the podcast... haha).