Update DboSource::group():

* Update documentation.
* Add Model type hint.
* Bail early when fields are empty.
Add more Model type hints, and ease the model testing replacing is_object() for  '!== null'.
Merge pull request #2438 from bar/2.5-console-options-format

Set console options in the same fashion for every shell/task.
Add test for saveMany + validate=false.

Closes #2468
Fixed docblock. Closes #2476
Fixed small coding standard error
Make Hash::numeric() accept more numeric things.

Negative numbers and other stringy forms of numbers should be accepted.
The name Hash::numeric implies is_numeric which it now uses.

Fixes #2478
Merge pull request #2458 from bar/2.5-model-typehints

Add Model type hints, and ease testing for Model.
Merge pull request #2350 from tuffz/formatting_app_uses_blocks

formatting app::uses blocks
fix CookieComponent - when write null or empty string
Merge branch 'master' into 2.5
Pull out some re-used subpatterns.

Having smaller segments makes reading the larger patterns simpler, and
allows for less duplication across the various patterns.

Refs #2436
Merge pull request #2482 from zoghal/2.5-cookie-fix2

fix CookieComponent - when write null or empty string
Relax the 'my' and 'ym' date validation formats.

All other formats that include 'y' allow 2006 or 06. These formats are
now conformant with the other formats available.

Closes #2436
Fix mixed tabs/spaces.
Make API docs easier to read.
Don't throw exception when trying to encrypt falsey value.
Merge pull request #2483 from ADmad/2.5-security

Don't throw exception when trying to encrypt falsey value.
Revert change done in 11f543f1f2.

The change is unneeded now as Security::encrypt() no longer throws exception
for falsey values.
Merge pull request #2484 from ADmad/2.5-cookiecomponent

Revert change done in 11f543f1f2.