modules/pv: added new $conid PV

- Returns the TCP connection ID that the current message arrived on (for
  TCP/TLS/WS/WSS) or $null (for UDP/SCTP)
modules/websocket: Added ws_close() exported function

- Enables immediate closure of a WebSocket connection from the configuration
  file.
modules/outbound: added warning message when outbound module is loaded in a configuraiton that does not load the stun module
modules/websocket: added warning when websocket module is loaded in a configuration without either the nathelper or outbound modules
modules/msrp: added warning when MSRP is loaded in a configuration without TLS.  TLS is mandatory for MSRP relays.
modules/msrp: Use "msrps://" URIs for the server when TLS is loaded. TLS is mandatory for MSRP relays.
modules/presence: downgraded unsupported event syslog message

- Downgraded unsupported event syslog message from error to notice.
modules/websocket: Added check to stop Kamailio starting if WebSocket is loaded without xhttp
modules/path: reduced the level of an outbound related diagnostic message
modules/rr: reduced the level of an outbound related diagnostic message
modules/rr: reduced the level of some outbound related diagnostics
modules/outbound: reduced the level of some outbound related diagnostics
msrp: cache in a local variable if tls module is loaded

- avoid looping at runtime through the list of modules
core: debug message to show mapping of routing block names to ids
tm: fixed warning related to failure branch routing block execution

- routing blocks id are >=1, the condition was always true because the
  field in tm struct is unsigned int
- gcc warning was: comparison is always true due to limited range of data
  type
Makefile.defs: devel version set to 4.1.0-dev4
modules/usrloc and registrar: added possibility to unregister without aor

- added possibility to unregister without aor if usrloc uses db_mode=3
- added new usrloc api function delete_urecord_by_ruid()
modules/usrloc: reduce work if contact attributes are not in use
utils/misc: updated vim syntax file