To be accurate, only their methods are excluded, the trait themselves are still available.

I also excluded a bunch of std traits by default. Some less opinionated, like `AsRef`, which should never be used directly except in generic scenarios (and won't be excluded there), some more opinionated, like the ops traits, which I know some users sometimes want to use directly. Either way it's configurable.

It should be pretty easy to extend support to excluding only specific methods, but I didn't do that currently.

Traits configured to be excluded are resolved in each completion request from scratch. If this proves too expensive, it is easy enough to cache them in the DB.

… the name

I.e. with `fn foo()`, don't complete at `x.fo|`, but complete (with imports) for `x.foo|`, since this is less likely to have false positives.

I opted to only do that for flyimport, even though for basic imports there can also be snippet completion (completing the params list for a method), since this is less universally applicable and seems not so useful.