Added yet unsupported TextualComponents
These methods are implemented as per the link below, but as they are
snapshot-only, they throw exceptions. However, the implementation is
present such that removing one line and one paragraph from the docs of
each method will make them complete and snapshot-client-compatible.

http://www.minecraftforum.net/topic/1975697-1718-raw-json-text-examples-for-tellraw-title-update14w20b/#SYNTAXtellraw
Implemented support for TextualComponent while keeping legacy methods.
Minimal API is broken: The only breaking change is then(Object) ->
then(String), however this is outweighted by the benefits
The example has not yet been updated
Updated example to use TextualComponent, as it was broken.
It is now ever so slightly less fluid as an Integer.toString call is
required to convert the primitive int to a String object.
Renamed TextualComponent factory methods.
They now make more sense, as you are more-or-less extracting
TextualComponents from data when you call them, less so creating them
with that data. (To me at least) it feels more intuitive to write using
these names.