Add class QgsComposerRuler
Add composer rulers to composer graphics view
Implement drawing of ruler markers
Fix ruler layout
Don't draw view frame (alignment with ruler widgets)
Fix calculation of ruler y-coordinates
Read composer from xml considers rulers
Better placement for y-coordinate labels
Show ruler marker for cursor position
Store reference to composition in ruler to get page info
Consider multiple pages for ruler scale
Improve coordinate display
Show snap lines in ruler mouse move event
Snap to arbitrary snap lines
Improve handling of snap lines
Implement moving of snapped features together with the snap line
Do not wait for feature form closing for non-editable layers
Move decay radio widget into advanced group box, and set the default value to 0. This method of controlling the kernel shape is non-standard, and should be achieved instead by giving users a choice of standard kernel functions.
[FEATURE] Add option to select kernel shape (quartic, triangular or uniform) in heatmap plugin
Merge heatmap_fixes branch