[folks] Pass the --driver version to valadoc to minimize complications.

[Travis Reitter <treitter src gnome org>]

commit f2ac22ee276ef9b7ae3e8baed920cc5d991b78ef
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Fri Jun 7 09:11:04 2013 -0700

    Pass the --driver version to valadoc to minimize complications.
    
    This ensures that we're building the library with the same version of Vala
    that valadoc uses

 docs/Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/docs/Makefile.am b/docs/Makefile.am
index de63c45..51efba4 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -70,6 +70,7 @@ valadoc_flags = \
        --force \
        --package-version $(PACKAGE_VERSION) \
        --no-protected \
+       --driver "$(shell valac --version)" \
        $(NULL)
 
 # folks documentation