INT-3356: Add `InboundChannelAdapter` Annotation

JIRA: https://jira.spring.io/browse/INT-3356

INT-3356 Polishing

Long lines and doc polish.
INT-1939 Twitter Search Outbound Gateway

JIRA: https://jira.spring.io/browse/INT-1939

Outbound gateway with `query-expression` and `limit-expression` to
allow on-demand variable searches.

Also add the `page-size` attribute to inbound adapters (previously
hard-coded to 20).

Also the inbound adapters now `require` a `TwitterTemplate` because even
search requires authentication.
Polishing - PR Comments

- Bump to spring-social-twitter 1.0.0.RC1
- Remove `requires-reply`
- Polishing
- Add integration test
INT-1939 Doc and Rework

After examining the Spring Social Twitter docs, there
are several search() methods on the SearchOperations.

Reworked the gateway so that the "search-args" can cause
any of those methods to be invoked, for maximumm flexibility.