Previously no gutter highlight was displayed unless
the selection was empty.
Now there is a separate CSS class for no selection
that changes the background color independently
from the foreground color.
When a command returned a large amount of data, it was blocking on the stderr callback when `[fileHandle availableData]` was called. From what I can tell, this is because stderr was being called with a zero-length string.
This was fixed when `[fileHandle availableData]` was moved to run inside the NSTask thread (instead of on the main thread). It now returns a zero-length string rather than blocking forever.
An unresolved question is why stderr is being called with zero-length strings.
Previously this data was only sent to the done
handlers and so commands such as SelectAllMatchesInProject
were not displaying all the results when the result size
was large.
