Security update for librsvg (moderate)

This update for librsvg fixes the following issues:

• CVE-2018-1000041: Input validation issue could lead to credentials leak.
  (bsc#1083232)

Update to version 2.40.20:

 + Except for emergencies, this will be the LAST RELEASE of the
   librsvg-2.40.x series.  We are moving to 2.41, which is vastly
   improved over the 2.40 series.  The API/ABI there remain unchaged, so
   we strongly encourage you to upgrade your sources and binaries to
   librsvg-2.41.x.
 + bgo#761175 - Allow masks and clips to reuse a node being drawn.
 + Don't access the file system when deciding whether to load a remote
   file with a UNC path for a paint server (i.e. don't try to load it at
   all).
 + Vistual Studio: fixed and integrated introspection builds, so
   introspection data is built directly from the Visual Studio project
   (Chun-wei Fan).
 + Visual Studio: We now use HIGHENTROPYVA linker option on x64 builds,
   to enhance the security of built binaries (Chun-wei Fan).
 + Fix generation of Vala bindings when compiling in read-only source
   directories (Emmanuele Bassi).

Update to version 2.40.19:

 + bgo#621088: Using text objects as clipping paths is now supported.
 + bgo#587721: Fix rendering of text elements with transformations
   (Massimo).
 + bgo#777833 - Fix memory leaks when an RsvgHandle is disposed before
   being closed (Philip Withnall).
 + bgo#782098 - Don't pass deprecated options to gtk-doc (Ting-Wei Lan).
 + bgo#786372 - Fix the default for the "type" attribute of the <style>
   element.
 + bgo#785276 - Don't crash on single-byte files.
 + bgo#634514: Don't render unknown elements and their sub-elements.
 + bgo#777155 - Ignore patterns that have close-to-zero dimensions.
 + bgo#634324 - Fix Gaussian blurs with negative scaling.
 + Fix the <switch> element; it wasn't working at all.
 + Fix loading when rsvg_handle_write() is called one byte at a time.
 + bgo#787895 - Fix incorrect usage of libxml2.  Thanks to Nick
   Wellnhofer for advice on this.
 + Backported the test suite machinery from the master branch (Chun-wei
   Fan, Federico Mena).
 + We now require Pango 1.38.0 or later (released in 2015).
 + We now require libxml2 2.9.0 or later (released in 2012).

This update was imported from the SUSE:SLE-12-SP2:Update update project.