fixed Temporal profile expression evaluation

added SpectralLibraryTableFilterModel

SpectralProfile inherits QgsFeature
SpectraLibrary inherits QgsVectorLayer

improved rendering dialog (WIP)

profile visualization: fixed TP loading status, added TP ContextMenu

fixed Issue #42

refactoring

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)

virtualrasters.py : added feature identify to preview map

added classificationscheme.py
utils.py added value2str
added vrtbuilder.ui
virtualrasters: multiple changes (in progress) related to vrtbuilder.ui

refactoring

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

SensorPlotStyle get restored
PixelLoader.py: CRS transformation in pure GDAL due to problems with QgsCoordinateTransformation in non-main thread
utils.geo2px() now casts geo2pxF coordinates to integer (instead of rounding them)

utils.py added loadIcon()
mapvisualization.py implemented MapCanvas loading activity bar

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

added sigShowVectorOverlay and sigRemoveVectorOverlay