CAMEL-6936: Fixed file/ftp consumer when idempotent=true may not detect file changed as new file, due the file was regarded as still in-progress.

Conflicts:
	camel-core/src/main/java/org/apache/camel/component/file/GenericFileConsumer.java
CAMEL-6990: Added language to Java DSL builder so it can be used more easily in the DSL. See ticket for example.
CAMEL-6936: Fixed file/ftp consumer when idempotent=true may not detect file changed as new file, due the file was regarded as still in-progress.
Fixed test
Fixed test