Prepared for the 15.11 release

Bugfix release 14.08.2

* SvxLink now compile in C++11 mode with GCC and other compilers that
  understand the -std=c++11 compiler switch. The compiler switch will
  automatically be turned on if a version of libsigc++ greater than 2.5.0
  is detected since those versions require C++11 to be enabled.

* Bugfix: The logic linking would cause a crash under some circumstances.  For
  example SvxLink would crash on startup if link TIMEOUT was set and the startup
  Tcl function was modified to play an audio clip.

Bugfix release 14.08.1

* Bugfix: Fixes issue sm0svx#87 "Suddenly stops speaking to the EchoLink directory
  server".

* ModuleEchoLink: If an incoming connect have a different IP address than
  the one registered in the Echolink directory server, the station list is now
  refreshed immediately instead of just rejecting the connection and wait for
  the next periodic refresh.

Release 14.08

Fixed some versions/dates that were wrong in the 13.12.1 release

Release 13.12

Release 13.07

Release 13.06

Release 13.03

Release 11.11.1