Support lasem-0.7

A new upstream released a new version:
https://github.com/mjakeman/lasem/releases/tag/LASEM_0_7_0

configure.ac

@@ -151,7 +151,7 @@ dnl ***********************
 
 goffice_with_lasem=false
 lasem=
-for ver in 0.6 0.4 ; do
+for ver in 0.7 0.6 0.4 ; do
   if test "x$lasem" = x; then
     if pkg-config --exists lasem-$ver; then
       lasem=lasem-$ver