Instead of the previous approach which relied on a side effect of
installing *-fonts parts that would write in parts/fonts/ and make the
fonts automatically available to applications, use a new approach where
each part is "pure", without side effects.
To make the fonts available to applications, a fontconfig font.conf
listing all the parts with fonts needs to be generated and set as
$FONTCONFIG environment variable.

A template font.conf is included in component/fontconfig

because fonts-* all write in same parts/fonts/ this cannot be shared
yet.

By default, /usr/X11R6/lib/X11 /usr/X11/lib/X11 /usr/lib/X11 are added
if they exist at compile time
https://cgit.freedesktop.org/fontconfig/tree/configure.ac?id=b546940435ebfb0df575bc7a2350d1e913919c34#n502
We prefer isolation from base system

Remove the comment questioning about --add-default-font because we don't
add fonts for this reason and also because users can use a $FONTCONFIG
file.

aspell-en-dictionary, groonga-normalizer-mysql, file-msooxml, apache-antiloris are not shareable, they write files in other parts.

https://cgit.freedesktop.org/fontconfig/commit/?id=1ab5258f7c2abfafcd63a760ca08bf93591912da

fontconfig > 2.12.1 now requires gperf.

This reverts commit 38123b86.

fontconfig was not building any more on many machines (most testnode machines). Revert
until investigation is done.

https://patchwork.openembedded.org/patch/134994/

also revert "revert libXrender version because building cairo-1.10.2 failed."
also cleanup PKG_CONFIG_PATH.
also cleanup boost-lib recipe.

Use slapos provided libraries by defined include and rpath

This reverts commit 1ea46ea8.

Don't use squash because in this way we will lost the history.

Create components and software (automagically).
Some components are candidates to merge, some to remove.
Some components shall be stacks.