This reverts commit cdb2c8a7.

This reverts commit 0704da57, reversing
changes made to 4534d449.

* Additional .gitignore entries

* Merge a bunch of small articles about system tables into single one

* Merge a bunch of small articles about formats into single one

* Adapt table with formats to English docs too

* Add SPb meetup link to main page

* Move Utilities out of top level of docs (the location is probably not yet final) + translate couple articles

* Merge MacOS.md into build_osx.md

* Move Data types higher in ToC

* Publish changelog on website alongside documentation

* Few fixes for en/table_engines/file.md

* Use smaller header sizes in changelogs

* Group up table engines inside ToC

* Move table engines out of top level too

* Specificy in ToC that query language is SQL based. Thats a bit excessive, but catches eye.

* Move stuff that is part of query language into respective folder

* Move table functions lower in ToC

* Lost redirects.txt update

* Do not rely on comments in yaml + fix few ru titles

* Extract major parts of queries.md into separate articles

* queries.md has been supposed to be removed

* Fix weird translation

* Fix a bunch of links

* There is only table of contents left

* "Query language" is actually part of SQL abbreviation

* Change filename in README.md too

* fix mistype

Merge remote-tracking branch 'upstream/master' into system-log-prepare-table-on-each-flush

#2131 deleted excessive logging

Revert "#2131 deleted excessive logging"

This reverts commit d78a46d9.

Revert "SystemLog: execute prepareTable()  on each flush"

This reverts commit 7f60bb0a.

SystemLog: execute prepareTable() on each flush

The lost information in the Kafka engine documentation has been restored, modified and translated (from commit: https://github.com/yandex/ClickHouse/pull/1654/files#diff-c9ba89e2414c83b5dcc579233c5c80b5)

Some links are fixed.

Russian sources are updated following the english ones.

Russian sources are updated following the english ones.