component/python2.7 Add extra-path variable to python buildout

This allows a recipe building python to add custom extra-path

component/python-2.7/buildout.cfg

@@ -56,9 +56,10 @@ configure-options =
 make-binary =
 make-targets = make profile-opt && make install
 
+extra-ldflags =
 # the entry "-Wl,-rpath=${file:location}/lib" below is needed by python-magic,
 # which would otherwise load the system libmagic.so with ctypes
 environment =
   PATH=${patch:location}/bin:${xz-utils:location}/bin:%(PATH)s
   CPPFLAGS=-I${zlib:location}/include -I${readline:location}/include -I${libexpat:location}/include -I${libffi:location}/include -I${ncurses:location}/include -I${ncurses:location}/include/ncursesw -I${bzip2:location}/include  -I${gdbm:location}/include -I${openssl:location}/include -I${sqlite3:location}/include -I${gettext:location}/include
-  LDFLAGS=-L${zlib:location}/lib -L${readline:location}/lib -L${libexpat:location}/lib -L${libffi:location}/lib -L${ncurses:location}/lib -L${bzip2:location}/lib -L${gdbm:location}/lib -L${openssl:location}/lib -L${sqlite3:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${readline:location}/lib -Wl,-rpath=${libexpat:location}/lib -Wl,-rpath=${libffi:location}/lib -Wl,-rpath=${ncurses:location}/lib -Wl,-rpath=${bzip2:location}/lib -Wl,-rpath=${gdbm:location}/lib -Wl,-rpath=${openssl:location}/lib -Wl,-rpath=${sqlite3:location}/lib -L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -Wl,-rpath=${file:location}/lib
+  LDFLAGS=-L${zlib:location}/lib -L${readline:location}/lib -L${libexpat:location}/lib -L${libffi:location}/lib -L${ncurses:location}/lib -L${bzip2:location}/lib -L${gdbm:location}/lib -L${openssl:location}/lib -L${sqlite3:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${readline:location}/lib -Wl,-rpath=${libexpat:location}/lib -Wl,-rpath=${libffi:location}/lib -Wl,-rpath=${ncurses:location}/lib -Wl,-rpath=${bzip2:location}/lib -Wl,-rpath=${gdbm:location}/lib -Wl,-rpath=${openssl:location}/lib -Wl,-rpath=${sqlite3:location}/lib -L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -Wl,-rpath=${file:location}/lib ${:extra-ldflags}