Disaster resistant alterSoup + Concurrency Protection 

Also:
reIndexSoup / clearSoup plugin actions support
a bunch of new tests

Alter soup code refactored to its own class AlterSoupLongOperation, a subclass of LongOperation.
New table long_operations_status to keep track and resume long operations (created by DBOpenHelper:onUpgrade for existing databases).
Long operations are resumed when db is open (DBOpenHelper:onOpen).