Fixed tests of migration commands.

Conflicts:
	src/Propel/Generator/Command/MigrationDiffCommand.php
Separated database agnostics tests and integration tests.

Conflicts:
	.coveralls.yml
	.travis.yml
	src/Propel/Generator/Command/MigrationUpCommand.php
	tests/Propel/Tests/Generator/Behavior/Sluggable/SluggableBehaviorTest.php
	tests/Propel/Tests/Runtime/Collection/CollectionTest.php
	tests/Propel/Tests/TestCase.php
	tests/bin/phpunit.mysql.sh
Setup only for integration tests
When DB is agnostic we use MysqlPlatform to build the fixtures model classes.
Renamed --exclude-schema to --exclude-database in TestPrepareCommand

Added some new filter for phpunit
Added test for TableDiff::__toString
Removed ObjectBuilder::addFKByKeyMutator because its nowhere used.

Conflicts:
	src/Propel/Generator/Builder/Om/ObjectBuilder.php
Removed DataSQLBuilder stuff as its not in use.

Conflicts:
	src/Propel/Generator/Builder/Sql/Pgsql/PgsqlDataSQLBuilder.php
Removed ColumnValue and DataRow classes

Conflicts:
	src/Propel/Generator/Builder/Util/DataRow.php
Removed doInsert in Runtime\Map\TableMap
Added test for Table::testIsIndex

Conflicts:
	tests/Propel/Tests/Generator/Model/TableTest.php
Fixed test suite for current master

if we migrate the database then it can be that columns order is different than defined in the schema.xml.
We use in our tests `SELECT *` which returns the columns in database order, not model order.
Improved test suite runtime drastically and remove travis jobs for hhvm+pgsql and hhvm+sqlite
Activated code coverage analysis