Fix travis builds.

Travis updated to phpunit 4 for PHP 5.3 and CakePHP needs phpunit 3.7.
Merge pull request #3431 from ADmad/2.4-travis

Fix travis builds.
This is a hotfix for TextHelper which seems to have gone wrong in a merge. tail() is missing completly and the docs for truncate() are the ones for tail(). This fixes it.
Correct documentation.
Merge pull request #3432 from dereuromark/master-hotfix

Hotfix - For TextHelper
Synchronize docblocks.
Tweak Validator API to be more user friendly.

Using `allowEmpty('field', false);` doesn't read as well as
`notEmpty('field)`. I feel the mode will be less frequently used over
setting a custom message, so switch the order of those parameters
around.
Update bake generated code to use new validator api.
merge fields and blacklist

rather than have an explicit blacklist - blacklist a field by
specifying it as false in $fields
test corrections
Merge pull request #3412 from dereuromark/2.6-overwrite

Backporting overwrite() from 3.0 to 2.6.
Add mode to notEmpty() and remove message from allowEmpty().

Having `$message` for allowEmpty() doesn't make sense as it will only
remove validation errors now, not cause them to be triggered. Add
`$mode` to notEmpty() as it is very relevant there.
Expand unit tests and fix issue with notEmpty().
Add additional tests for intersection of notEmpty()/allowEmpty()
Merge branch 'master' into 2.5

Conflicts:
	lib/Cake/Model/Datasource/DboSource.php
	lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php
	lib/Cake/Utility/Folder.php
	lib/Cake/VERSION.txt
Merge pull request #3435 from markstory/3.0-validation-tweaks

RFC - 3.0 validation tweaks
Merge branch '2.5' into 2.6
add a test that the "blacklist" does something
Merge pull request #3436 from AD7six/3.0-form-inputs-blacklist

RFC: merge blacklist and fields for Form::inputs
Stricter string comparisons.