Grammar.parse :args support

See https://github.com/perl6/specs/commit/67579a1cf7
https://github.com/perl6/roast/commit/1bc8a5fee6
work around Parrot's INIT difficulties

Using INIT here doesn't buy us anything in any case.
work around parrot INIT problems

But we still need to wait till main's run time.
add travis build status image
Don't complain if we don't test anything
Make Str.lines much simpler, a little faster still

/usr/share/dict/words: 2.383 -> 2.082, about 13%
Add :eager candidates for Str.lines, 5x faster!

So the lazy form is still the default: the eager version could be used when
needed, or when the optimizer determines it can (in the future).
Add :eager candidates to IO::Handle.lines

/usr/share/dict/words: 2.787s -> 0.768s (about 3.5x as fast)
Add some comments about eager candidates
Pass on --ll-exception in precomping process
Lazily initialize $*THREAD
update ROADMAP

* add @<> regex feature, vendethiel++
* remove duplicate mention of coercions
Mention Proc::Async

Even though it was in the previous release already
Add Kernel.signal to get kernel signal values

Either takes a string, or Signal Enum.  Please note that we cannot reliably
map the Signal Enum to Kernel signal values, as these may (and do) differ per
kernel.
Get Kernel.signal up to spec  :-)
Again, bring Kernel.signal up to spec
Add Str.IO.watch, remove need for code stubs

This will probably need a reconfigure to work.
Fix copynpasto/thinko in chars/bytes logic
Streamline Supply generating code
Implement :%ENV for Proc::Async.start, as per spec