labeling.py refactoring, improved return values for QgsVectorFile editing

Merge branch 'feature/labeling' of https://bitbucket.org/jakimowb/eo-time-series-viewer into feature/labeling

labeling.py MapCanvas context menu show shortcuts to label on selected QgsFeatures in linked QgsVectorLayer fields

added global accessors to labelshortcut layers

added LabelAttributeTableModel.shortcuts(QgsField)->list of auto-labels

added LabelAttributeType, LabelAttributeTableModel, LabelingDock

- Keys as shortcut to access EO TSV settings
- settings are restored during start of EO TSV
timeseriesviewer.settings.value(..., default=...) und .setValue(...) as counterparts to QSettings object
- added SettingsDialog

fixed several bugs and errors
mapcanvases changes now applied not immediately but within timed interals (500msec by default)

- added MapCanvasLayerModel, MapCanvas.Command, multi-raster-layer support
- implemented refresh pipeline for timed updates
- QMenu shows Crosshair visibility, fixed some api bugs
- added setSpatialExtent, setSpatialCenter
- spatialExtentHint considers all layers

TimeSeriesViewer:
- added showTimeSeriesDatum fpor scrolling to TSD of interest

TimeSeries + TimeSeriesTableModel + panel:
- support multiple raster per date
- QSortProxyModel allows sorting

utils.py
- added some more TestObject functions

make.py
- resource.py compilation is now python-only.
refactoring + docstrings

sensorID checks for supported data types
refactoring