Merge latest changes. 
The Typemapper was merged into de.zalando namespace, therefore
@DatabaseField and @DatabaseType need to be reimported from new
namespace.

Minor changes include:
 - fix in java.sql.Timestamp parsing
 - camelCase to camel_case was not 100% the same in sproc wrapper and
type mapper
 - transaction ids for distributed transactions are now identical
 - searchShards checks return properly
 - significant performance improvements in Typemapper
 
Credit for original Typemapper goes to Daniel N. and Valentine G.