KMatplot

This release adds cut/copy/paste, undo/redo, a formula parser (still under development), a colored area under the surface, v-gradient, plotting of 4d data (still under development), custom tics values, fast selecting of graph elements by middle button click, and grouping/ungrouping of objects. It allows many pages in a single document. Axes can be freely added to / removed from a graph. Surfaces and contours can display non-gridded data (using Delunay triangulation). The general data storing policy has changed; vectors are stored as columns. There are many bugfixes.