fixed unicode string
added example section to the documentation
Merge branch 'feature/examples'
improved setup documentation, added reference to examples
improved note about preconditions
added general notes for examples
added detailed description of example 1
added example 2
added example 2 to documentation
fixed references to orbit_framework.messaging.Slot in module orbit_framework
code cleanup
added example 3
added documentation for example 3
added default value documentation to SingleDeviceCallback
Merge branch 'master' into feature/examples
Merge branch 'feature/examples'