[iOS 5] Change deployment target to 5.0

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[iOS 5] Add helpers to detect system version

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[iOS 5] Add support to UUIDs

iOS 5 doesn't support Apple IFA or IFV. So, we need to generate our own UUID, using CFUUID.

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[iOS 5] strong vs. assign on dispatch_queue_t @property

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[iOS 5] Add support to ISO8601 with TZ with :

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[UUID] Use a common UUID generator to the entire Liquid

* If device is running iOS < 6.0: `NSUUID` is used
* If device is running iOS >= 6.0: `CFUUID` is used

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[LQQueue] Add random factor to next try date

In order to avoid too much requests at the same time,
a random factor was added to the number of seconds to increment until next try.

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[Asserts] Unification of assertAttribute:andKey: method

`assertAttributeType:` and `assertAttributeKey:`
unified in:
`assertAttributeType:andKey:`

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[Asserts] Asserts now produce a warning, if in production

* A new Log level was introduced: `kLQLogLevelAssert` (default for production)
* `LQLog()` now outputs in production too

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
Merge branch 'asserts' into development
Merge branch 'ios5_support' into development

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>

Conflicts:
	Liquid/LQDefaults.h
Small fix in randomInt: return value data type

Changed from NSInteger to NSUInteger and fixed a cast warning.

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>