[unix] Call libtool to clean up.

* builds/unix/install.mk (clean_project_unix, distclean_project_unix):
Use libtool.
* builds/freetype.mk: Minor.
diff --git a/ChangeLog b/ChangeLog
index c9d5be1..8b3b75c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-01-21  Alexei Podtelezhnikov  <apodtele@gmail.com>
+
+	[unix] Call libtool to clean up.
+
+	* builds/unix/install.mk (clean_project_unix, distclean_project_unix):
+	Use libtool.
+	* builds/freetype.mk: Minor.
+
 2018-01-18  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	* src/base/ftver.rc: Fix mingw-w64 compilation.
diff --git a/builds/freetype.mk b/builds/freetype.mk
index 447b4a3..6f68a0f 100644
--- a/builds/freetype.mk
+++ b/builds/freetype.mk
@@ -345,10 +345,9 @@
 
 .PHONY: clean distclean
 
-# The `config.mk' file must define `clean_freetype' and
-# `distclean_freetype'.  Implementations may use to relay these to either
-# the `std' or `dos' versions from above, or simply provide their own
-# implementation.
+# The `config.mk' file must define `clean_project' and `distclean_project'.
+# Implementations may use to relay these to either the `std' or `dos'
+# versions from above, or simply provide their own implementation.
 #
 clean: clean_project
 distclean: distclean_project remove_config_mk remove_ftmodule_h
diff --git a/builds/unix/install.mk b/builds/unix/install.mk
index 50325ca..d89064e 100644
--- a/builds/unix/install.mk
+++ b/builds/unix/install.mk
@@ -88,13 +88,11 @@
 # Unix cleaning and distclean rules.
 #
 clean_project_unix:
-	-$(DELETE) $(BASE_OBJECTS) $(OBJ_M) $(OBJ_S)
-	-$(DELETE) $(patsubst %.$O,%.$(SO),$(BASE_OBJECTS) $(OBJ_M) $(OBJ_S)) \
-                   $(CLEAN)
+	-$(LIBTOOL) --mode=clean $(RM) $(OBJECTS_LIST)
+	-$(DELETE) $(CLEAN)
 
 distclean_project_unix: clean_project_unix
-	-$(DELETE) $(PROJECT_LIBRARY)
-	-$(DELDIR) $(OBJ_DIR)/.libs
+	-$(LIBTOOL) --mode=clean $(RM) $(PROJECT_LIBRARY)
 	-$(DELETE) *.orig *~ core *.core $(DISTCLEAN)
 
 # EOF