JCBC-190: Allow ComplexKeys to work with all kinds of numbers.

This changeset switches from parsing longs to the more generic
NumberFormat.parse method. This allows the usage of integers,
doubles, floats and longs at the same time. See the updated
test cases for examples.

Change-Id: Id7b906958d1bbd75a1319aedffa0e8b6211dc9d6
Reviewed-on: http://review.couchbase.org/23605
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>