Add documentation on DBAL query builder
Discuss safe and unsafe APIs in security chapter
Reshuffle security chapter
save one columns iteration in comparator table diff
Merge pull request #427 from deeky666/optimize-comparator-table-diff

Save one columns iteration in Comparator::diffTable
fix typo
fix link in documentation
Merge pull request #431 from deeky666/DBAL-683

[DBAL-683] Fix link to known vendor issues in documentation
set mysqli driver options before real connect
Merge pull request #432 from deeky666/fix-mysqli-driver-options

Fix mysqli driver options
fix adding primary key during table alteration in MySQL
Merge pull request #435 from deeky666/DBAL-400

[DBAL-400] Fix adding primary key during table alteration in MySQL