Change automake python macro to get python path

Previously install path for python binding is fixed, as
lib/python2.7/site-packages and other version/enironement is not
supported. This change introduces automake's python macro and gets
the install path from environment dynamically.

Change-Id: I6535107d4bde61976fbdf5392d460beb1049658e
Signed-off-by: Tomofumi Hayashi <tohayash@redhat.com>

src/configure.ac

@@ -10,6 +10,7 @@ AC_PROG_CC
 AM_PROG_AS
 AM_PROG_LIBTOOL
 AC_PROG_YACC
+AM_PATH_PYTHON
 
 AM_CONDITIONAL([CROSSCOMPILE], [test "$cross_compiling" == "yes"])
 

src/vpp-api/python/Makefile.am

@@ -41,7 +41,8 @@ libpneum_la_CPPFLAGS =
 # TODO: Support both Python 2 and 3.
 install-exec-local:
 	cd $(srcdir);							\
-	mkdir -p $(prefix)/lib/python2.7/site-packages; 		\
+	mkdir -p $(pythondir);						\
+	mkdir -p $(pyexecdir); 						\
 	PYTHONUSERBASE=$(prefix)					\
 	python setup.py build_ext -L $(libdir)				\
 	-I $(prefix)/include/ install --user