Updated pointer file, storeAIP, and metadata entry for AIC

refs #5803

SIPs now store a sipType, which is "SIP" by default but is "AIC" for AICs.
AIP Pointer File stores the correct package type, pulled from the Dublin
Core metadata.  Store AIP sends package type of AIC when sipType is AIC.
Removed dependency on Django for store AIP.  The metadata entry form shows
the AIC form if the sipType is AIC, and the default DublinCore form
otherwise.

Also, fixed bug in dublin core METS creation.