Remove white space excess
Merge pull request #4097 from deerawan/development

Fix json format in gii/generators/extension/default
add caching-page.md
Upgraded Bootstrap from 3.1 to 3.2
fix link
add caching-fragment.md
[Uk][Guide] intro-yii.md [skip ci]
Merge pull request #4099 from dilip-vishwa/patch-5

Upgrade Bootstrap from 3.1 to 3.2
Improved references to Composer packages in docs
add caching-http.md
typo fixes [skip ci]
add concept-aliases.md
Merge remote-tracking branch 'upstream/master' into upstream

* upstream/master:
  typo fixes [skip ci]
Fixes #4098: `yii\db\Query::addSelect()` should include `*` when it is called the first time
Merge branch 'master' of git://github.com/yiisoft/yii2
typo fix
fix duplicated white space and typo [skip ci]
add concept-autoloading.md -wip
Merge pull request #4101 from qiansen1386/patch-10

fix duplicated white space and typo [skip ci]
Reverted #4098.