MimeTypeController generates a map of file extensions to MIME types

It uses `mime.types` file from apache http located under
http://svn.apache.org/viewvc/httpd/httpd/trunk/docs/conf/mime.types?view=markup

This file has been placed in the public domain for unlimited
redistribution,
so we can use it and ship it with Yii.

see also yiisoft/yii#2851 and yiisoft/yii#2857

added class references (current version without hyperlink)

better usage of URL in latex

- better title page,
- book style,
- improved internal linking using labels and references

Route parameter url encoding added

Fix ErrorHandler

Update rest-quick-start.md: highlight automatic pluralization

bad grammar

This is probably not expected given the other naming conventions within Yii, so highlight this feature for beginners.

Hotfix for #3597

Improved array support for "data" attribute in renderTagAttributes()

typo

Incomplete obsolete filling in i18n db extractor