Fixes #1405: fixed disambiguation of relation names generated by gii.
configs fixed and improved
added testcase for unit tests, bootstrap files improved, tests inherited from base testcase
Create ColumnSchema.php
Create QueryBuilder.php
Create Schema.php
Sphinx test AR classes moved to 'data/ar/sphinx'.
Sphinx Active Record refactored to extend "BaseActiveRecord".
Method "yii\sphinx\ActiveRecord::find()" removed in favour of "BaseActiveRecord::find()".
Merge branch 'master' of github.com:yiisoft/yii2 into mongo
Method "execute()" added to Mongo Database.
Broken example of mail component usage
Merge pull request #1409 from crtlib/patch-1

Broken example of mail component usage
Mongo Collection "group" and "mapReduce" functions fixed.
Mongo Collection "aggregate" method interface refactored.
Mongo Collection "deleteAllIndexes" return result fixed.
Mongo Collection "findAll" method removed.
Logging and profiling for Mongo Query added.
Doc comments at Mongo updated.
Doc comments at Mongo updated.
Fixes #1402: AR eager loading has problem when asArray() is used together with viaTable().