Merge tag '4.1.0' into develop

v4.1.0

- New: DefinedSwitches::getSwitchesInDisplayOrder() can now return a list
  minus the actsAsCommand switches, on request
New: support for implicit values for arguments
New: $switch->setLongDescription()
New: can now obtain a list of switches that are commands
Version bump
Merge branch 'release/4.2.0'