Restrict disabling foreign keys to MySQL when dropping objects. See http://www.heidisql.com/forum.php?t=7025#p16142

git-svn-id: http://heidisql.googlecode.com/svn/trunk@4801 560a3889-bb33-0410-9f33-43a8a102dc09
Support older PostgreSQL servers in TPGConnection.FetchDbObjects. See http://www.heidisql.com/forum.php?t=16072#p16138

git-svn-id: http://heidisql.googlecode.com/svn/trunk@4802 560a3889-bb33-0410-9f33-43a8a102dc09
Remove unused variables

git-svn-id: http://heidisql.googlecode.com/svn/trunk@4803 560a3889-bb33-0410-9f33-43a8a102dc09
Use SUBSTR() alternative to LEFT() on PostgreSQL table data selection. See http://www.heidisql.com/forum.php?t=16072

git-svn-id: http://heidisql.googlecode.com/svn/trunk@4804 560a3889-bb33-0410-9f33-43a8a102dc09