* Make npm run-script completion faster with `jq`
When jq is available, it's actually faster to invoke jq and parse the `package.json`
invoking the `npm` command.
Also, prior to this commit, both `__fish_complete_npm` and `__fish_npm_run` were being run
whenever completions for `npm run` subcommand was being used, which was actually making
repetitive work (invoking npm command twice). This pull request is supposed to make completion
without `jq` faster as well
* Refactor npm.fish for code reutilization
Created function to handle both cases of npm run completion parse, with or without `jq` completion.
* Remove unecessary blank line
I believe apm must have been buggy - example output that I found online
showed `tr` was mangling paths with spaces in it. Should be fixed.
Also, use dscl on OS X in __fish_complete_users.fish like
__fish_print_users.fish already does.
This is already done by fish before calling the completion.
It breaks completion with combiners (#2025) and also with wrappers.
(This does not include git because that's better solved in #2145)
