Changed the way closure compiler is run to use nailgun

[hmedhat]

I was trying to find an alternative for plovr while development, because plovr is a little bit far behind and upgrading google closure every time is becoming troublesome there.

So I considered using gulp. I set up a gulp webserver using gulp connect and on fallback, it triggers the google closure compile, then it waits until the file is generated and it will then serve it to the client. The problem that I am facing is that the compile time is much bigger than plovr ~40s vs ~20s. So I managed to solve that by using nailgun to run the jar, and this way I can avoid the overhead of the jvm run time. and I actually reached the same compile time as plovr.

The is only one problem with this pull request that using running closure compiler using src won't work anymore, it gives that error in from the compile process error

{ Error: Nailgun failed to start up.
    at NailgunServer._receiveServerClose (/home/hatem/coscale/interfaces/app/node_modules/node-nailgun/src/NailgunServer.js:107:19)
    at emitTwo (events.js:106:13)
    at ChildProcess.emit (events.js:191:7)
    at maybeClose (internal/child_process.js:920:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:230:5)
  nailgunStdout: 'com.martiansoftware.nailgun.builtins.NGAlias: 0/0\ncom.martiansoftware.nailgun.builtins.NGClasspath: 0/0\ncom.martiansoftware.nailgun.builtins.NGServerStats: 0/0\ncom.martiansoftware.nailgun.builtins.NGStop: 0/0\ncom.martiansoftware.nailgun.builtins.NGVersion: 0/0\nNGServer shut down.\n' }

I could not find the solution for this problem, so any help here would be appreciated.

Here is a link for my initial problem:
https://stackoverflow.com/questions/46957958/decreasing-google-closure-run-time-using-gulp

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[hmedhat]

I signed it!

[googlebot]

CLAs look good, thanks!

[ChadKillingsworth]

I love the idea of nailgun and actually would like to make it the default for webpack when a watch mode is implemented. However there would be substantial pushback from users requiring it for this plugin. Best bet would be to create a new nailgun specific project that has google-closure-compiler as a dependency.

There are specific hooks in this project which allow the use of nailgun. See #51.

I would definitely entertain adding a section to the readme at the bottom discussing how to do this.