h2o: add package

H2O is a new generation HTTP server that provides quicker response to users
  with less CPU utilization when compared to older generation of web servers.
  Designed from ground-up, the server takes full advantage of HTTP/2 features
  including prioritized content serving and server push, promising outstanding
  experience to the visitors of your web site.

Signed-off-by: James Taylor <james@jtaylor.id.au>

libs/h2o/patches/200-libh2o-evloop_wslay-link.patch

@@ -0,0 +1,9 @@
+--- a/libh2o-evloop.pc.in
++++ b/libh2o-evloop.pc.in
+@@ -7,5 +7,5 @@
+ Description: An optimized HTTP/1.x & HTTP/2 library
+ URL: https://h2o.examp1e.net/
+ Version: @LIBRARY_VERSION_MAJOR@.@LIBRARY_VERSION_MINOR@.@LIBRARY_VERSION_PATCH@
+-Libs: -L${libdir} -lh2o-evloop
++Libs: -L${libdir} -lh2o-evloop -lwslay
+ Cflags: -I${includedir}