New API to create or open multi-user case and store connection info

bindings/java/jni/dataModel_SleuthkitJNI.cpp

bindings/java/jni/dataModel_SleuthkitJNI.h

tsk/auto/Makefile.am

tsk/auto/case_db.cpp

tsk/auto/db_connection_info.h

tsk/auto/db_postgresql.cpp

tsk/auto/tsk_case_db.h

tsk/auto/tsk_db.cpp

tsk/auto/tsk_db.h

tsk/auto/tsk_db_postgresql.h

win32/libtsk/libtsk.vcxproj

win32/libtsk/libtsk.vcxproj.filters