ENYO-2711: Add enyo.version string indicating current version, current one is "2.3.0-alpha.pilot4"

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Update version number and scheme based on feedback from Gray

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Fleshing out explanatory text, bumping version number.

Since we've already pushed out the fourth pre-release for 2.3, we're now working on 2.3.0-pre.5.
Merge pull request #344 from enyojs/ENYO-2711-unwiredben

ENYO-2711: Add enyo.version string indicating current version, current o...