get rid off upgrading errors for plugins table
moved plugins upgrade script to separate file
require database_conf file to perform sql queries
upgrading guide improvement
added more steps to upgrade guide
revert upgrade.php to working version
fixed handling upgrading errors
fixed logging errors when upgading newscoop
CS-5514 - Overwriting database is not working in 4.3 installer
Merge pull request #825 from takeit/master

Upgrading 4.2.3/4.2.4 to 4.3 fixes