Adds a Metamorph function for generating timestamps.
(cherry picked from commit 0b882feac55b075e27239d733e83a4e576ff0862)
Adds a dateformat function to Metamorph for converting various date formats.

(cherry picked from commit 0b882feac55b075e27239d733e83a4e576ff0862)
(cherry picked from commit 37f4a547cddeff57a4f954150a121b142357f41f)

Conflicts:
	src/main/java/org/culturegraph/mf/morph/functions/DateFormat.java
Adds pretty printing and configurable character escapes to the JsonEncoder.

(cherry picking from commit 0b882feac55b075e27239d733e83a4e576ff0862)
Adds the ability to escape the @-character in Metamorph names

Metamorph uses the @-character to mark data that should be fed back into
Metamorph for a second round of processing. However, sometimes one wants
to uses an @ in a key name without triggering the feedback loop.

(cherry picked from commit 0b882feac55b075e27239d733e83a4e576ff0862)
(cherry picked from commit 7e8189b2659f583c13b825910d2b4b623311bce8)
Modifies the Counter module to allow pipe lining

Additionally, this commits makes the module available in Flux. That
is not really useful but helps finding the module.

(cherry picked from commit eaf9153e887eefad316f7c646f42c06ea5c265cc)