Fixes #4453: `yii message/extract` wasn't properly writing to po files in case of multiple categories

Corrected table name

Update schema-mssql.sql

MSSQL syntax fix

Update start-databases.md

INSERT queries didn't work with first letter capitalized in table name.

double word "from"

fix the link

close #4436

Generate Traditional Chinese messages

Removed double quotes

Added Traditional Chinese translations

Removed Sphinx installation from foreign PPA

https://getcomposer.org/doc/03-cli.md#require

Fixes #3957: Added more straightforward configurable properties to `BlameableBehavior`, `SluggableBehavior` and `TimestampBehavior`

Fixes #4409: Upper case letters in subdirectory prefixes of controller IDs were not properly handled