MD-302
DicomDatabase creation/deletion is time-consuming : limitation
Warning message in debug mode
IndependentDatabase when copying files locally

Main database created on main thread
MD-285
DicomDatabase: faster databaseForContext function
MD-304
WebPortal: minimum width for rendering as a NSDefaults value
MD-305
DCMPix: limit number of processors for multi-threading function
Merge remote-tracking branch 'upstream/develop' into develop