fix link to update operators in MongoDB manual

Related note: I think the MongoDB folks say "update operators" where
they used to say "update modifiers", so we may want to follow their
lead.
give a suggestion for how to name your package
Use ChildProcess kill method to reload CSS

Using the method instead of process.kill means that we don't send the
signal if we already know the process is dead and that we don't throw on
ESRCH (ie, the kernel telling us the process is gone).  (If the process
has already died we will soon get around to doing a different kind of
restart.)

Fixes #2550.
Revert accidental watch change from 78497c0

Fixes #2550.
It is not true anymore that one cannot store EJSON in the database.
Skip ResolverState clone on duplicate constraint
Improve error message on one particular conflict
refactor tests