Fixed "Undefined variable" in migration:status

Fixed "Undefined variable: oldestMigrationTimestamp" when running "migration:status" without "-v"
fixed enum param/return type
Merge pull request #514 from gharlan/enum-docs

Wrong phpdoc for enum getters and setters
Merge pull request #540 from livioribeiro/patch-1

Fixes "Undefined variable" in migration:status
php 5.6 support

Adding php 5.6 on travis ci testing
Merge pull request #544 from gmsantosxl/master

php 5.6 support
Improvement to develop behaviors
PropelColumnTypes class used by bindValue method
optimized generated classes
add "isser" methods for boolean columns
Fixed MigrationManager::getMigrationDir call which should be MigrationManager::getWorkingDir instead
Merge pull request #552 from mpscholten/bug-fix-for-531

Fixed #531 "Missing method 'getMigrationDir' in MigrationManager"
Merge pull request #546 from nekufa/patch-1

PropelColumnTypes class used by bindValue method
Merge pull request #547 from gharlan/isser-methods

Add "isser" methods for boolean columns
Merge pull request #541 from gharlan/optimized-generated-classes

optimized generated classes
Update UniqueValidator.php

        $object     = $this->context->getRoot();
        $className  = get_class($object);

are not needed because Symfony\Component\Validator\ExecutionContext provides a getClassName() method. Also, $this->context->getRoot() was returning a Form object, which does not have the TABLE_MAP constant defined.
Merge pull request #555 from dsoares/patch-1

Update UniqueValidator.php
added ConnectionInterface type hints
removed SqlConnectionInterface
travis: use fast_finish option