Support relative imports

[ashleyh]

The following is currently a parse error:

from .a import b

[JukkaL]

Also from . import x does not work.

[mason-bially]

I ran into this error too, there appears a need to add the ability to deal with a dot here in the parse unfortunately, I'm not sure what that would mean for the rest of the import code which will need to support it.

[mason-bially]

Would need to expand this node (and the one below) to deal with it, likely a relative file-name (or just a bool if it's available elsewhere in the tree).

[JukkaL]

I guess anybody can finish the implementation, as it seems that @mason-bially is no longer working on this. If nobody else picks this up, I might work on this in the next couple of weeks, since this is a pretty major missing feature.