gtk-doc-1.22 change wrt to tmpl builds

[Stefan Sauer <ensonic hora-obscura de>]

Hi,

The upcoming gtk-doc-1.22 release will switch the default makefile
flavour from "legacy" to "no-tmpl".
If your configure.ac had a line such as
GTK_DOC_CHECK([1.XX])
without any args you were using a doc build that includes the deprecated
'tmpl' build step. If you the tmpl directory is not committed to your
version control than you are fine. If the tmpl dir is in version
control, please check if you are ever edited documentation in the files
in those directories. If no, remove the dir and change your configure.ac
macro to GTK_DOC_CHECK([1.XX],[--flavour no-tmpl]). If you edited the
tmpl files, please consider moving the docs to the sources, this is the
only model we support in the long run. To keep the project building with
gtk-doc-1.22, explicitly specify the makefile flavour:
GTK_DOC_CHECK([1.XX],[--flavour legacy]). We plan to drop the tooling
for tmpl files in one of the next releases. Please get in touch with us,
if you have trouble with the migration.

If you specified the makefile-flavour like in:
GTK_DOC_CHECK([1.XX],[--flavour no-tmpl])
you already use a build that does not use tmpl files and nothing will
change for you.

We are doing this to simplify the doc build. Maintaining comments in the
sources will increase the change that they are keept up-to-date. Having
generated files that need to be committed to source control systems is a
pain, as the files tend to differ if developers have different versions
of the generating tool. And finally dropping this intermediate step
makes the doc build a little faster.

Stefan