Beginning of doc update

Just getting the theme working and custom .mtt files implemented
Added a close button to the Popup class

A formatted button with an "x" that closes the popup when you click on it. Must explicitly set config.closeButton to "true" for it to enable.
Updated buildConfig in PopupManager to copy config

Before, custom configuration options were lost. This change makes custom options pass through. Added to support the closeButton configuration option that I added in my previous commit.
doc update
Merge pull request #176 from drezabek94/master

Add a close button to Popup's title bar
Fix for #178
Fix for #177
Fix for #173
Added sprite container
Small fixes
ScrollView fix
Fix for #179
Fix for #180
Slightly cleaner preloader
Merge branch 'master' of https://github.com/ianharrigan/haxeui into templ2