Version 0.16

Fixed functionality of 'togglePriorityClicked'
Version 0.161

New method: 'write_presets_XML' saving placeholder values
Version 0.162

New method: 'read_presets_XML' which reads presets from XML and stores
them in the self.presets variable
Version 0.163

Added comboBox with list of presets
When preset is selected, values are applied
Selecting 'No preset' does not change anything

At the moment, changing the values after applying a preset does not set
the preset to 'No Preset'. This should be changed.
Version 0.1631

The version of the application is not stored in a class variable called
'self._version'
Version 0.164

Added a value in the preferences that allows to define the path of the
presets file. This will allow different departments to have their own
preset file and not get all the presets defined by other teams.

At the moment, changing the values after applying a preset does not set
the preset to 'No Preset'. This should be changed.