Added timeout handling for command line modules.
Add time-out in ms for XML retrieval for local process
Add timeout exception type
Throw ctkCmdLineModuleTimeoutException when local process times-out retrieving xml
Use try/catch and debug output when extracting xml
Don't cache XML if it was a timeout
Tweak error message format
Add ability to replace CLI backend
Merge branch 'cli-timeout' of https://github.com/saschazelzer/CTK into 376-handle-timeout-retrieving-xml

Conflicts:
	Libs/CommandLineModules/Backend/LocalProcess/ctkCmdLineModuleBackendLocalProcess.cpp
	Libs/CommandLineModules/Core/ctkCmdLineModuleManager.cpp
	Libs/CommandLineModules/Core/ctkCmdLineModuleManager.h
	Libs/CommandLineModules/Core/ctkCmdLineModuleTimeoutException.cpp
	Libs/CommandLineModules/Core/ctkCmdLineModuleTimeoutException.h
Enable timeout to be specified via MainWindow
Put messageBoxModuleRegistration back in
Trap exceptions from concurrent registrations of CLI and report error messages and references
Stop reloadModules crashing
Added timeOutForXmlRetrieval to the module backend class.
Added method documentation.
Added methods to retrieve registered backends from the module manager.
Added unit tests for CLM timeout and caching handling.
Merge branch '376-handle-timeout-retrieving-xml'

* 376-handle-timeout-retrieving-xml:
  Added unit tests for CLM timeout and caching handling.
  Added methods to retrieve registered backends from the module manager.
  Added method documentation.
  Added timeOutForXmlRetrieval to the module backend class.
  Stop reloadModules crashing
  Trap exceptions from concurrent registrations of CLI and report error messages and references
  Put messageBoxModuleRegistration back in
  Enable timeout to be specified via MainWindow
  Add ability to replace CLI backend
  Tweak error message format
  Don't cache XML if it was a timeout
  Use try/catch and debug output when extracting xml
  Throw ctkCmdLineModuleTimeoutException when local process times-out retrieving xml
  Add timeout exception type
  Add time-out in ms for XML retrieval for local process
  Added timeout handling for command line modules.