Close the session out before erasing all the fixtures.

Not closing the session before closing fixtures results in fatal errors
when using database sessions.

Fixes #3683
Disable the cache when running schema commands.

This prevents stale cached schema definitions from preventing updates.

Fixes #3690
Fix dropTables being ignore in some cases.

When autoFixtures = false & dropTables = false, individually loaded
fixtures should not be dropped.

Fixes #3691
add CONTRIBUTING.md
Throw exceptions when non Datasource classes are used as Datasources.

Using models as datasources can cause segmentation faults. Guard against
that by checking types and raising exceptions early.

Fixes #3694
Fixed PHPUnit include bug.

Fixed vendor include path bug.
Added test for CakeTestSuiteDispatcher::loadTestFramework.
Added test for CakeTestSuiteDispatcher::loadTestFramework.
Merge branch 'master' of github.com:psparrow/cakephp

Conflicts:
	lib/Cake/Test/Case/TestSuite/CakeTestSuiteDispatcherTest.php
Fixed code formatting.
Merge branch 'master' of github.com:psparrow/cakephp
Throw exceptions only when datasource has wrong package, not check for instance of Datasource
fix failing tests. test and mocked sources would cause exceptions
Merge pull request #1176 from ceeram/2.3-3694

Throw exceptions only when datasource has wrong package.

This is replaces instanceof checks with a more generalized check. 

Refs #3694
Force & when creating requests.

Some people will have entities in arg_seperator.output. Make HttpSocket
more resiliant.

Fixes #3692
Move tests around.

Try to fix timing issues in formhelper tests.
Fix issue with midnight hour & 12hr formats.

No hour would be selected in the case of 12hr formats and a time like
00:xx:yy
Fix alphaNumeric validation
fix failing test with webrunner
Merge pull request #1177 from yuya-takeyama/fix-alphaNumeric-validation

Fix alphaNumeric validation