DSL: O-Gs: `requiresReply="true"` by default

Since many `outbound-gateway`s are designed to always expect replies and XML configuration
specifies `requires-reply="true"` for them by default, the DSL should follow with that.
INTEXT-111: Allow PP for Kafka producer context

JIRA: https://jira.spring.io/browse/INTEXT-111

 - Remove hard coded names for bean names at the producer context parser
 - Fix and update tests
 - Remove the use of `BeanFactory` to get the producerConfigurations in
KakfaProducerContext and use setter to set the producerConfigurations
 - Add logic to send the message from producer configuration when there
is no header specified for the topic and single producer configuration
is used.

Add tests to verify placeholder values

Fix code review comment and formatting

Polishing code style.

Add `KafkaProducerContext#theProducerConfiguration` for single `producerConfigurations` entry to avoid iterators
[artifactory-release] Release version Kafka 1.0.0.M2
[artifactory-release] Kafka Next development version
Add StringDecoder for kafka messages

 - Add StringDecoder for decoding kafka key/value messages

Refactor StringDecoder
[artifactory-release] Release version Kafka 1.0.0.M2 (#2)
[artifactory-release] Kafka Next development version
DSL: Move Java DSL to the separate repo
INTEXT-118: Fox for long messages with newlines

JIRA: https://jira.spring.io/browse/INTEXT-118

It also tests long messages without newlines to verify that the fix works for both types of long messages.

INTEXT-118: Replace regular expression split with standard substring to split message into subparts with max length.
The regular expression used earlier failed splitting messages that contained newlines correctly. (See SmesMessageSpecificationTest)

Corrected spelling in constants

Polishing
Move Splunk to the individual repo
Move `Kafka` to the separate repo
Move AWS to separate repo
INTEXT-39 Remove Experimental WebSocket Code

JIRA: https://jira.spring.io/browse/INTEXT-39
INTEXT-122: Make XSD versionless from SI-core XSD

JIRA: https://jira.spring.io/browse/INTEXT-122

Fix for SMPP. All other extensions will be fixed on demand, when they will be upgraded to SI 4.0 or higher