extracted methods from tbl_relation.php to tbl_relation.lib.php for rendering html
added methods PMA_sendHtmlForTableOrColumnDropdownList, PMA_sendHtmlForColumnDorpdownList, PMA_sendHtmlForTableDropdownList
added methods PMA_handleUpdateForDisplayField, PMA_getQueryForDisplayUpdate
Merge pull request #650 from scnakandala/refac_tbl_relation.php

Refactoring tbl_relation.php
Fix typos
bug #3993 Sorting in database overview with statistics doesn't work
Fix merge conflicts
Another foreign key definition for information_schema
Translated using Weblate (Simplified Chinese)

Currently translated at 95.1% (2586 of 2720)
Merge remote-tracking branch 'origin/master'
Merge branch 'master' of https://github.com/phpmyadmin/phpmyadmin into refactor_server_databasesss