Fix: checkstyle
Fix: ON DELETE CASCADE is forbidden.

Conflicts:
	htdocs/install/mysql/migration/3.6.0-3.7.0.sql
	test/phpunit/SqlTest.php
Fix: Pb with migration with pgsql
Fix: Migration does not match tables
Merge remote-tracking branch 'origin/3.6' into develop

Conflicts:
	htdocs/install/mysql/tables/llx_expeditiondet_batch.key.sql
	htdocs/install/mysql/tables/llx_product_batch.key.sql
Fix: sql syntax error
New: Add country iso code on 3 chars into table of countries.
Merge remote-tracking branch 'origin/3.6' into develop