Support ISO8601 milliseconds at dateForKey:fallback:

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Code bautification

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Using strong data_types on Liquid Variables

Liquid Package now includes data types. When a liquid variable is used,
if data type doesn't match, fallback variable is used.

Changes were done on cached Liquid Package. So, to ensure legacy, previous
cached liquid package is destroyed after update.

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Send fallback variables/values to server in development mode

Each tiem a variable is used, it is sent to server (POST), in dev mode.
This will populate variables and values on Liquid dashboard.

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
LiquidPackage uses NSError when values are not found

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Small fix when sending null values to server

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Do not send null fallback values to server, for now

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Storing more data on cached Liquid Package

* Storing `targetId` (`target_id`) at cached Liquid Package's `LQValue`

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Fix on LQValue.targetId class

NSInteger to NSString

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Fallbacks invalidate all other variables of same target

Each time a variable falls back to its fallback value, all the other variables
of covered by the same target are also invalidated (fallen back).

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>
Add soft and hard reset methods

* Soft reset: Will reset all liquid (dynamic variable) to its fallback values. A new session is created, and user attributes are reset.
* Hard reset: Will reset Liquid as soft reset does, but also remove all queued HTTP requests.

Signed-off-by: Miguel M. Almeida <miguelcma@CMA-Retina.local>