issue #1659: released buildLimitOffset() for MSSQL

Doc typo

Fix typos in constant

doc fix

fixes #2132, fixes #2133

Updated doc about using jar files from other location

Ensure that the table prefix is used when generating the class name.

Updated doc about using jar files such as compiler.jar and yuicompressor.jar from other location then the default specified.

GridView typo fixed

Fixes #2079

- DbMessageSource now performs UNION ALL.
- Fixed message merging for php and po.
- Updated tests.

Conflicts:
	framework/CHANGELOG.md

Update QueryBuilder.php and Query.php

Added one line about support of UNION ALL queries.

Comment test because it proceed an errors when tries to run at mssql and other DBMS.

Change <code>array_reduce</code> with anonimous function variant to easy string collection from pieces of unions.

Using short array syntax.

issue #1797

Add test for UNION/UNION ALL function.
It could be useful to use "phpunit --group=db --filter testBuildUnion" command for run it.

Change buildUnion method to be ready to accept parameters in <code>['all' => $all, 'query' => $query]</code> format for division to "UNION" and "UNION ALL" constructions.

Change passing parameters to array with two elements – 'all' which means if we use UNION or UNION ALL construction and 'query' which is our sql query that will be at right of construction.