Removed extraneous mutex

The mutex lives in Creativity now; the code was actually fine: it was
just locking both its own (pointlessly--that mutex wasn't used anywhere
else) and the Creativity one as well.
Changed application ID (was just a test value)
Use explicit type instead of implicit decltype(.)
Added ability to load command line creativity file
throwParseError() was an infinite loop
Added Storage.flush() virtual method

MemoryStorage doesn't need it (and so the default no-op is fine), but
FileStorage does.
Continuation block writing and reading was broken

The continuation block would be written out, but its location was never
stored in the header (or previous cblock).

A typo meant that reading a continuation block was also broken ('block'
should have been 'cblock').
Added command-line interface to running sims

The CLI only writes .crstate files; the GUI can then load them to
visualize the result.