Connection: Replaced ! is_int with is_string

Intended side effect is not to call extractTypeValues when $types array is empty which it is by default.
add servicename connection parameter to Oracle drivers
fix foreign key columns order in Oracle
fix column default value introspection in Oracle
fix foreign key propagation on non-supporting MySQL table engines
fix parsing backtick quoted statement fragments
Merge pull request #477 from deeky666/DBAL-552

[DBAL-552] Fix parsing backtick quoted statement fragments in SQLParserUtils
Merge pull request #476 from deeky666/fix-mysql-foreign-key-creation

Fix foreign key propagation on non-supporting MySQL table engines
Merge pull request #475 from deeky666/fix-oracle-default-value-introspection

Fix column default value introspection in Oracle
Merge pull request #474 from deeky666/fix-oracle-list-composite-foreign-keys

Fix foreign key columns order in Oracle
Merge pull request #471 from deeky666/DBAL-685

[DBAL-685] Add servicename connection parameter to Oracle drivers
Merge pull request #470 from mishak87/patch-1

Connection: Replaced ! is_int with is_string