CharFields replaced by IntegerFields in LBaaS forms.

The following fields were changed:
* Vip / protocol port
* Vip / connection limit
* Member / protocol port
* Member / weight
* Monitor / delay
* Monitor / timeout
* Monitor / max_retries

Added range validations:
* Vip / protocol port -- in range [1..65535]
* Vip / connection limit -- more or equal that 0 or -1 if the limit is not set
* Member / protocol port -- in range [1..65535]
* Member / weight -- in range [0..256]
* Monitor / delay -- more or equal that 1
* Monitor / timeout -- more or equal that 1
* Monitor / max_retries -- in range [1..10]

Fixes bug 1153525

Change-Id: I7bf9fe24060dc85076d9be2e6592a51a33fefeae
Merge "CharFields replaced by IntegerFields in LBaaS forms."