first draft of the extension generator
Merge branch 'master' into feature/gii-extension-generator
minor docs update (still WIP)
Merge commit 'fcac7f64b37c6a8d4ead9816b2580f50580c540d' into feature/gii-extension-generator
updated defaults, UI, validation and templates
refactored apidoc extensions completely.

separated guide and apidoc, better maintainability
added safe validator for keywords
updated docs and hints
fixed typos
updated CHANGELOG
fixed order
CONTrack Setup: Yii2 Advanced Template
Initialize CONTrack - Database, Name, Email
CONTrack Configuration for Hosting per Aaron Francis
CONTrack Configuration - urlManager, yii2helpers - Kartik
CONTrack Configuration - Add Gii Module to Each App
Merge pull request #2411 from schmunk42/feature/gii-extension-generator

first draft of the extension generator
Gii extension generator adjustments
Fixed action beforeRun/afterRun calls.
Fixes #2552.