Due to the way matroska headers directly reference ebml headers, you'll have to configure like this:
CPPFLAGS=-I/usr/local/include/ebml ./configure --enable-mkv
* configure.ac:
+ Added curly braces around variables.
+ Got rid of the "x$foo" constructs.
+ Renamed *_plugin conditionals into *_p.
* debian/changelog:
+ Fixed a duplicate entry.
+ Added an entry for an old Debian upload that fixed#117180.
* debian/control:
+ Added a build dependency on libimlib2-dev for skins.
* debian/rules:
+ Activated support for skins.