Do not use g_type_init() for newer versions of GLib
Fix up several warnings spotted when building the distro package

...which uses '-Wformat' by default.
Set several warning flags and fix up the trivial issues
Fix the schema install logic

We can't use a test on pythondir/lxml as the former will have a non-expanded prefix in some cases.
Ensure the tarball is always built with schemas enabled
trivial: Fix ChangeLog generation
Release version 0.1.6