Update README.md

Added closing parenthesis on the first sentence of the License section.
Merge pull request #1914 from glennon/patch-1

Update README.md
iwyu
svg_renderer: use precision of 4, accept map request/scale_factor, and fix output of multipart geometries
spirit::karma based to_hex_string generator
+ to_string based on spirit::karma for completeness.
catch boost::filesystem::directory_iterator::construct error and print warning rather than throwing exception - closes #1919 - refs mapbox/tilemill#1992
+ fix typo in grammar
iwyu
svg_renderer: start paying attention to scale_factor, collision, and fonts
svg_renderer: only process line/polygon symbolizers as <path> for now
svg_renderer: group layers in inkscape capatible way - refs #1917
protect against negative image dimensions - closes #1927
support scale_denominator override in save_to_cairo_file - closes #1930
add expected (currently failing) test for #1931
fix behavior of marker-ignore-placement on lines - closes #1931
remove debugging line
Add test for translating geometries
Merge pull request #1932 from ajashton/geom-translate-test

Add test for translating geometries
fix #1933 by ensuring that only tests for valid plugins are run