Draft: add implementation for roles and permission rules.

include/CMakeLists.txt

include/caosdb/acm/permission_rule.h

include/caosdb/acm/role.h

include/caosdb/connection.h

src/CMakeLists.txt

src/caosdb/acm/permission_rule.cpp

src/caosdb/acm/permission_rule_impl.h

src/caosdb/acm/role.cpp

src/caosdb/acm/role_impl.h

src/caosdb/connection.cpp

src/cxxcaosdbcli.cpp

test/CMakeLists.txt

test/test_connection.cpp

test/test_role.cpp