dbmanager: rotating layer import and export icons to more intuitive sense
advanced digitizing tools
this integrates advanced digitizing tools aka CAD tools in QGIS application and basically a port of CADinput plugin
* new class QgsMapToolAdvancedDigitizing shall be subsclassed if adv. digit. tools could be used in a map tool
* QgsAdvancedDigitizingDockWidget handles the interaction with the user and also perform the constraints (filters events)
* QgsAdvancedDigitizingCanvasItem paints construction lines on the canvas
[processing] [feature] split lines with lines
[expressions] Make int/int return double results.

Also add a new "//" operator to perform integer division.
(fix #5153)
[gui] Fix fieldcalculator layout
[gui] Fix qgsexpressionbuilder layout
Log error to ProcessingLog
Merge pull request #1719 from bstroebl/splitLines

[processing] [feature] split lines with lines
dxf export:
* export layers in reversed rendering order
* use checkboxes for layer selection
* support for layers selection by visibility preset
* improve selection of layer attribute
* show busy cursor while exporting
* fix duplicate end of entities section
indentation update
Merge pull request #1721 from nyalldawson/integer_divide

[expressions] Make int/int return double results
Merge pull request #1517 from imincik/dbmanager_icons

dbmanager: rotating layer import and export icons to more intuitive sense
Ensure all items are deleted from TestQgsComposerTableV2
Add note about QgsMapCanvas::rotation() being added in 2.8
Make toCanvasCoordinate(QRect) method private in QgsMapCanvasItem

I added this for rotation support but the interface is probably not
something any external code should rely upon.
Export QgsMapSettings rotation API to python
debian packaging update (merge and squash PR#1725)
Expose QgsMapCanvas rotation and centering API to python
Merge pull request #1624 from 3nids/cadtool_single

Advanced digitizing tools (aka CAD tools)
Add unit test for QgsMapToPixel (legacy only for now)