Discussions page

I created a page public_html/discussions.php that uses the Meetup Class to fetch info from our Meetup discussions board. Also modified the class with some comments and an additional method that was necessary to show replies to posts. 

Also slightly changed the index.php to use the Meetup API to limit responses Meetup sends instead of getting them all and only displaying the first few. Updated the nav-bar to have link to discussion page.

Tried to be better about comments and writing cleanler. It is something I'm working on to be a better programmer. 
id put a space before and after str concats. ex

'this is' . 'a string';