added field mapping to config for Harvard Library Cloud
client: some bug fixes wrt error reporting
API: fixed problem with error reporting

this bug was introduced in commit 1805c53fad9cbad3c489785d9d15847b7d8c3c67
SparQl adapter: removed hard coded object type
SparQL: fields are requested OPTIONAL; return id
Memcache: bug fix; note for Franz wrt further bugs
SparQL: implemented resolveId correctly