Update ObjectBuilder.php

Add `@throws` phpdocs in enum getter/setter.
Update QueryBuilder.php

Add `@throws` phpdocs for `findPkSimple` and `filterByXXX`
added migrationDir config option
Propel2-710 Propel compatibility with Symfony 2.5 components

added check for LegacyValidator class in order to load the correct Validator classes below SF 2.5 and from 2.5
replaced BufferedOutput with StreamOutput class which is available since SF 2.3
changed symfony requirements to ~2.3

fixes #710
remove isRequired from connection classname config
Fix #709
Fix #712
PDO (and many other builtin functions) does not like extra parameters

PDOException : SQLSTATE[HY000]: General error: Extraneous additional parameters

refs c174239 #588
refs fca101a
more fetchAll tests
Update OracleSchemaParser.php

syntax error
Fix link to the contribution guideline [ci skip]
Merge pull request #727 from robin850/readme-contribute-link

Fix link to the contribution guideline
Merge pull request #726 from Userator/patch-1

Update OracleSchemaParser.php
reverse command: change argument mode

for loading connection data from configuration file
fixed generator for locale_column parameter
Added testcase for the fix
Created i18n_pk_column parameter which allow to set custom primary key column on i18n table
Split the configuration definition
Merge pull request #716 from nymo/Fix-Propel2-710-compability-with-SF-2.5

Propel2-710 Propel compatibility with Symfony 2.5 components
Merge pull request #718 from gharlan/migration-dir-config-option

migrationDir config option