Expose option to override properties included on Plugin Error, copy all properties from original error by default

[mtscout6]

Currently when you create a PluginError with an existing error the properties of the original error are lost unless they are included on an internal list of white listed properties. I propose two enhancements:

1. Provide a means to override the white listed properties.
2. If no white list properties are provided, then include all properties from the original error.

[mtscout6]

I would think this should require a minor revision bump.

[coveralls]

Coverage remained the same when pulling 164b968 on mtscout6:plugin-error-properties into 4c94141 on gulpjs:master.

[yocontra]

if you're using lodash for only one function, use the split out version. the module for this would be lodash.uniq

[sindresorhus]

or just https://github.com/sindresorhus/array-uniq which is completely self-contained.

[coveralls]

Coverage remained the same when pulling 1e0f24e on mtscout6:plugin-error-properties into 4c94141 on gulpjs:master.

[mtscout6]

What's the verdict on this?

[yocontra]

needs a rebase for merge

[coveralls]

Coverage remained the same when pulling 2703722 on mtscout6:plugin-error-properties into a44e450 on gulpjs:master.

[mtscout6]

Rebased!

[yocontra]

My only complaint is the "properties" field name - I think we need something a little more descriptive. What does "properties" mean if I do new PluginError('plugin name', 'error msg', {properties: ?})

[mtscout6]

How does errorPropertiesToCopy sound? Or do you have a better alternative?

[yocontra]

I'll take another PR documenting these changes before I publish