Version 0.4
New feature: added simple algorithm, based ona area preservation idea, for
generalisation of lines with orthogonal segments, e.g. buildings
Fixed bug: Preprocesing of neighbour double points in point lists corrected.
Fixed bug: Map layer combobox in dialog now filters only polyline and polygon
layers, avoiding errors when raster layers are present in project, during
vertices counting.
Fixed bug: Corrected output for input lines with only four points.
Version 0.3
Fixed bug: Generalisation could result in features with empty geometries.
Added selection of algorithm used: default is simplification+smoothing, now only
simplification or only smoothing can be applied.
Improved performance of estimation of number of vertices and time needed for
generalisation.
Closed LineString objects are generalised same as LinearRing objects
(starting/ending point can be modified)
Code improved, cleaned and better documented.
Version 0.2
More robust computation in case of collinear points.
