UNDERTOW-81 Prevent nested invocation of ServletRequestListener
Add the concept of exchange attributes

These will be used to provide consistency across features, such as the access log,
rewrite handler, page cache etc.
Add ability to reference variables from the predicate context
Varargs support for predicate expressions
Add more predicate and attribute types
Move content encoding logic into its own class
Add support for combing multiple authentication mechanisms
Add initial support for serving pre-compressed resources
UNDERTOW-82 NPE in AsyncContextImpl
Modify exchange attributes to better support specifying redirects
Wire up redirect handler to use new functionality
More predicate and attribute related fixes
Add handler that can be used to set arbitrary attributes on the exchange
Add full rewrite handler support
Add method predicate
Add support for configuring handlers via text based config
Clean up predicated handlers implementation
Fix issue with web socket chat example
Undertow 1.0.0.Beta1
Next is Beta2