Update to experimental r13565

Update to experimental r13543

More header cleanup

Add closePath().

Add closePath().

DrawingContext: change variable names ct to dc (bug #1272073)

Partial fix for blocker bug 1163449: "Imported bitmap appear blurry when zoomed in" Setting style to include "image-rendering:optimizeSpeed" will cause nearest neighbor filter to be used in downscaling.

changes_2013_05_22a.patch: 1. Resolves issue of bug #988601 message 170 (Support of 'Unset' styles in EMF export). 2. Implements CSS 3 (and CSS 2) text-decoration support. Note that it does not yet provide any method of adding these features - at present it just shows whatever is in the SVG. This new code is also used to display EMF/WMF strike-through and underline text decorations when these files are read in. Those decorations may also be written out to EMF/WMF. Other text decoration features, like overline, or dotted lines, are dropped. For SVG text-decoration -line, -style, -color are all implemented. CSS3 provides two ways to represent the same state, this code uses the compound text-decoration method rather than the 3 fields method. Also it leaves out keywords that are not needed and would break backwards compatibility. For instance: text-decoration: underline solid is valid, but would break CSS2. Solid is the default, so that sort of case is written as: text-decoration: underline If the state is CSS3 specific all of the needed fields are of course include, like text-decoration: underline wavy red 3. It incorporates the fix for bug 1181326 (Text edit mishandles span of just colored spaces) 4. It incorporates further changes to text editing so that style can be changed on spans consisting of only spaces when text decorations are present in the span. 5. It incorporates code to disable text decorations when text so marked is mapped onto a path. 6. Fixed more bugs in Hebrew language support than I can remember. Hebrew language export/import to EMF now works quite well. (See the examples in libTERE v 0.7.) WMF does not support unicode and for all intents and purposes Inkscape has no way to read or write Hebrew to it. Some of more important things that now work that didn't (or didn't always): Hebrew diacritical marks, R/L/center justification, and bidirectional text. The Hebrew fonts "Ezra SIL" and "EZRA SIL SR" should be installed before viewing the libTERE examples, otherwise font substitutions will cause some text shifts. 7. Implemented font failover in Text Reassemble, which makes the process more robust. (Again, see the examples in libTERE. )

Fix for #955141: Converting clipped object to pattern produces rasterised pattern.

Next pass of doxygen @brief cleanup.

Use cache even if only part of the redraw region is clean

Per-item render cache. Cache some offscreen data to facilitate smoother navigation.

Replace direct use of Cairo contexts and surfaces in the rendering tree with wrappers which keep some extra information about the surface, amd NRRect and NRRectL use with Geom::Rect and Geom::IntRect. Should simplify implementing filter primitive subregions.