[READY] Compression and mangle options for uglifyjs when building

I've noticed that in the past the dist build has not been compiled with the Mangle and Compress flags (-m and -c respectively).

I was wondering if this was a deliberate style choice, perhaps for debugging with the minified build.

Minifying with these options shows an almost 25% reduction in file size against the existing minified document.
```
$ uglifyjs Imager.js | wc -c
    6663

$ uglifyjs Imager.js -c -m | wc -c
    5014
```

Also, the minified build hasn't been rebuilt in 2 months.