ccid-emulator: Build libopensc from source code

There is no longer an external (or stable) interface for libopensc.
Linking this program with an existing version of libopensc that is
pre-installed in the system library paths is not practical.

However, a specific snapshot of the OpenSC source code is embedded
here as a Git submodule (and included in the source distributions).
Build libopensc from this and statically link it into this program.
(Options such as '--enable-openpace' that are passed to ./configure
will be forwarded to control the build configuration of libopensc.)

Remove code that existed for compatibility when dynamically linking
with older versions of libopensc.

ccid/doc/Makefile.am

@@ -13,7 +13,6 @@ do_subst = $(SED) \
 	   -e 's,[@]libdir[@],$(libdir),g' \
 	   -e 's,[@]includedir[@],$(includedir),g' \
 	   -e 's,[@]VERSION[@],$(VERSION),g' \
-	   -e 's,[@]OPENSC_LIBS[@],$(OPENSC_LIBS),g' \
 	   -e 's,[@]abs_top_srcdir[@],$(abs_top_srcdir),g' \
 	   -e 's,[@]top_srcdir[@],$(top_srcdir),g'