build: Fix srcdir != builddir from git

Make it possible to build the source out-of-tree. The gnome-continuous
build system does this by default.

Signed-off-by: Colin Walters <walters@verbum.org>
[rydberg@euromail.se: Resolve merge conflict]
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Release mtdev-1.1.5

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>