Force a consistent order onto Article's Set fields before printing to JSON
Use first contiguous string of digits as the volumeNumber

Previously, for a volume string like "80(1)", the transform provided "801"
as the volumeNumber. Change it to use the first contiguous, non-empty
sequence of digit characters ("80") as the volumeNumber, defaulting to the
old value if there is no match.
Merge branch 'volume-number' into casegen

Conflicts:
	src/main/java/org/ambraproject/article/service/XslIngestArchiveProcessor.java

Conflict was on import statements only.