[multi-sources-removal] Simplify ConnectionsSet internal structures and public methods
since it now handles a connection to the system source only
Related to #2919300
[jcr: adjust 3.17.11 migration, fix a number of bugs in new
ConnectionsSet implementation, fix
source.{open,close}_source_connections]
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception