Wrote a test utility for displaying SVG images.
Exporting in SVG is now possible. Changed some SVG files to look a little nicer.
Merge remote-tracking branch 'realbinglebob/master'

Conflicts:
	src/main/java/com/cburch/draw/model/AbstractCanvasObject.java
	src/main/java/com/cburch/draw/shapes/Curve.java
	src/main/java/com/cburch/draw/shapes/Line.java
	src/main/java/com/cburch/draw/shapes/Oval.java
	src/main/java/com/cburch/draw/shapes/Poly.java
	src/main/java/com/cburch/draw/shapes/Rectangle.java
	src/main/java/com/cburch/draw/shapes/RoundRectangle.java
	src/main/java/com/cburch/draw/shapes/SvgCreator.java
	src/main/java/com/cburch/draw/shapes/SvgReader.java
	src/main/java/com/cburch/draw/shapes/Text.java
	src/main/java/com/cburch/draw/tools/SVGIcon.java
	src/main/java/com/cburch/logisim/circuit/appear/AppearanceAnchor.java
	src/main/java/com/cburch/logisim/circuit/appear/AppearancePort.java
	src/main/java/com/cburch/logisim/circuit/appear/AppearanceSvgReader.java
	src/main/java/com/cburch/logisim/file/XmlWriter.java
	src/main/java/com/cburch/logisim/gui/main/ExportImage.java
	src/main/java/com/cburch/logisim/gui/start/About.java
	src/main/java/com/cburch/logisim/std/gates/NorGate.java
	src/main/java/com/cburch/logisim/std/gates/PainterShaped.java
Implemented SLF4J as logger and started migration

* Made gradle build script dependencies easier to read
* Changed gradle build script from tabs to spaces
* Added some javadocs where appropriate