add some files to the distribution

Makefile.am

@@ -12,7 +12,8 @@ EXTRA_DIST = FAQ autogen.sh Stuarts_Poly_Notes  \
 		xgraph/aclocal.m4 \
 		build-for-mac-os.sh \
 		cross-compile.sh cross-compile-shared.sh \
-		compile_min.sh compile_linux.sh .gitignore
+		compile_min.sh compile_linux.sh compile_min_shared.sh \
+		ngspice.pc.in .gitignore
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 ar-lib compile config.guess \
 			src/include/ngspice/config.h.in config.sub configure install-sh \