Merge branch lp:~louis-simard/scour/rework. Summary of changes:

scour.py, scour.inkscape.py, scour.inx:
 * Add options --quiet, --enable-comment-stripping, --shorten-ids, --remove-metadata, --renderer-workaround.
scour.py:
 * Optimisations in time (so Scour runs faster) and space (so Scour allocates less memory, less often).
 * Change #E+# to #e#, #E-# to #e-#, 0.# to .# and -0.# into -.# in path/polygon/polyline data + lengths, if renderer workarounds are disabled. Use spaces instead of commas in path/polygon/polyline data. Use lower-case #rrggbb and #rgb instead of upper-case. All of this makes gzip work better, since the rest of SVG documents mostly has lower-case letters in tag names and spaces to separate XML attributes etc.
 * Fix a bug whereby an SVG document would become filled with black if all elements had the same fill color.
 * Fix a bug whereby a path's second command would not start at the right coordinates if the first command was a relative moveto 'm' with at least 1 implied lineto.
 * Fix a bug whereby a path's absolute lineto 'L' commands would not become the right relative lineto 'l' commands.
 * Allow the implicit linetos after a path's moveto 'M'/'m' to be converted into relative horizontal linetos 'h' and vertical 'v' too.
scour.inx:
 * Fix help typos. Make options more descriptive in the plugin option window. Add something about enable-group-collapsing requiring enable-id-stripping.
testscour.py:
 * Rework tests that relied on #E+#, #E-#, 0.# and -0.# so that they accept the changes to scour.py. Add unit tests for strip-xml-prolog, enable-comment-stripping and remove-metadata.

unittests/comment-beside-xml-decl.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+<!-- Oh look a comment -->
+<svg xmlns="http://www.w3.org/2000/svg">
+</svg>

unittests/full-metadata.svg

@@ -0,0 +1,22 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+    <metadata>
+      <rdf:RDF
+           xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+           xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#"
+           xmlns:dc = "http://purl.org/dc/elements/1.1/" >
+        <rdf:Description about="http://example.org/myfoo"
+             dc:title="MyFoo"
+             dc:description="Unit test for Scour's --remove-metadata option"
+             dc:publisher="No One"
+             dc:date="2010-06-09"
+             dc:format="image/svg+xml"
+             dc:language="en" >
+          <dc:creator>
+            <rdf:Bag>
+              <rdf:li>No One</rdf:li>
+            </rdf:Bag>
+          </dc:creator>
+        </rdf:Description>
+      </rdf:RDF>
+    </metadata>
+</svg>

unittests/shorten-ids.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200">
+	<defs>
+		<linearGradient id="this-abomination-should-be-shortened-to-a-single-letter">
+			<stop offset="0" stop-color="black" />
+			<stop offset="1" stop-color="white" />
+		</linearGradient>
+	</defs>
+	<rect fill="url(#this-abomination-should-be-shortened-to-a-single-letter)" x="20" y="20" width="160" height="160" />
+</svg>