consistent use of @env vs env

[StefanKarpinski]

I'd like to propose consistently using @env as syntax for a named environment with name env. This would allow doing something like pkg> activate @devtools to activate ~/.julia/environments/devtools no matter where you are. The main issue would seem to be conflicting with the @1.1 version syntax, but I'm not sure that's an actual ambiguity anywhere. Thoughts?

[fredrikekre]

And remove --shared?

[StefanKarpinski]

This does seem like it would be more intuitive, doesn't it? I always forget about shared and I want to just call named environments @env everywhere.

[KristofferC]

Seems like a simplification. @name if you just want to identify it by name. path/name if you want to identify by path.

[StefanKarpinski]

Note that as part of this we should use @env consistently to display shared environments as well. So the prompt should be (@v1.1) pkg> instead of the current (v1.1) pkg>. The idea is that if you do pkg> activate @v1.1 then the prompt you get afterwards is (@v1.1) pkg>.