Vision document for H1 2018

[Andrei Alexandrescu]

Hello, the vision document of the Founation for the first six months of 
2018 is here:

https://wiki.dlang.org/Vision/2018H1

In addition to the expected items, we have a new top-level priority - 
locking down the language definition. This is in recognition of the fact 
that we need a precise definition of the language going forward.


Thanks,

Andrei