[oe] X11R7.2 / epoch support

[pHilipp Zabel]

Hi openembedded-devel,

Yesterday we added the Xorg X11R7.2 release to OpenEmbedded. It is
noteworthy that the packages make use of bitbake/OE's new epoch
support. They drop the temporary X11R7.x_-prefix from their PV version
and instead set the epoch to PE = "1".

This means that bitbake releases without epoch handling (currently up
to 1.8) will think that for example a version X11R7.1_1.1.0 is newer
than 1:1.2.0. To be able to build the new packages with bitbake 1.6 or
1.8, you need to set PREFERRED_VERSIONs. As usual, we have
conf/distro/include/preferred-xorg-versions-X11R7.2.inc for that
reason. The angstrom distro already includes this and therefore now
ships X11R7.2 by default.

The OE epoch support consists of changes to package_ipk.bb and
package_deb.bb to write the epoch into the package control file. I
don't know if other package formats than ipk or deb support epochs
(rpm?) - patches welcome.

happy testing
Philipp