simplified MapViews and lazy rendering

Signed-off-by: benjamin.jakimow <benjamin.jakimow@geo.hu-berlin.de>

fixed bug in vector layer visualization
pulled qps updates

labeling.py refactoring, improved return values for QgsVectorFile editing

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

refactoring MapView dock

refactoring (import statements)

SpectralLibraryWidget (wip)

utils.py refactoring (loadUi -> loadUI, affects many widget classes)

added cursorlocationvalue.py + panel
added spectrallibraries.py + panel
added a couple of new icons
added trees.py (basic TreeModel system)

added # -*- coding: uft-8 -*-   and  # noinspection PyPep8Naming to each module
added GPL License statement to each module
added from __future__ import absolute_import to each module

moved loadUIFormClass(jp(DIR_UI, p)) to utils.py and (yessss!) removed an error occurred with newline character in *.ui inline HTML