ceylon.test: add TapLoggingListener

for Test Anything Protocol, version 13.
http://testanything.org/tap-version-13-specification.html
ceylon.test: add --tap option for TapLoggingListener
ceylon.test: TapLoggingListener: move plan to top

The “plan” is the number of tests you want to run, like `1..10`. The
intention is that even if the test runner crashes, you can still know
how far you got, and how many tests should be considered failed. This,
of course, only works if you print the plan right at the beginning.
ceylon.test: add __tap version for TAP, test-js
ceylon.test: ws

I didn’t understand @thradec’s whitespace policy at first, sorry!
Merge pull request #215 from lucaswerkmeister/testTap

ceylon.test: add support for Test Anything Protocol