* GH-3336: Change MongoDb Store sequence to long
Fixes https://github.com/spring-projects/spring-integration/issues/3336
Turns out there are some scenarios where too many messages
are transferred through the message store, so `int` for
sequence is not enough as a type
* Change sequence to `long` to widen a sequence lifespan
* * Change MongoDb store to deal with `Number.longValue()`
instead of casting which doesn't work from `Integer` to `Long`.
This way we can keep an old sequence document with an `int`
type for value
* Documents with new `long` type for their sequence field are OK.
The `NumberToNumberConverter` has an effect converting `int` to `long`
properly.
7a97eb6e1c