Fixes issue #545: PageCache doesn't work.
Improve application speed by using classMap for autoloader
moved classMap to separate file
rename classMap.php -> classes.php
Better handling of sending response content.
Implemented language negotiation.
Implemented Request::getAcceptedContentTypes().
updated basic app dependencies
fixes #549: ability to use HTMLPurifier multiple times
Merge pull request #550 from cebe/speed

Improve application speed by using classMap for autoloader
Fixed jsonp response handling.
Removed composer.lock from all apps. Currently it creates more problems since framework code changes rapidly.
fixed advanced app aliases
fixed advanced app contact form