Boost 1.50 built into a side tag

[Petr Machata]

Hi all,

this is to let you know that boost has been upgraded to 1.50, sans
Python 3 support, which will arrive later.

After complaints in past years, we decided to request a dedicated
side-tag ("f18-boost") not to break a hundred or so packages that depend
on it in Rawhide.  As always, all client packages, especially those that
depend on boost runtime libraries, need to be rebuilt, but this time
around you need to request the right tag explicitly:

        fedpkg build --target=f18-boost

This tag will live for a couple weeks, but I think we should merge back
before alpha freeze, which is 2012-08-14, in about two weeks.

There's at least one disruptive change that I know about:
Boost.Filesystem v2 has been discontinued and anyone who hasn't yet
ported their code to v3 must do so now.

As usual, feel free to open bugs, ping me on IRC (_petr) or send e-mails
if one of your packages doesn't like the new boost.  We'll figure out
how to work around the notorious API changes.  (Or fix boost.)

Thank you,
Petr Machata

Related:
https://fedoraproject.org/wiki/Features/F18Boost150
https://bugzilla.redhat.com/show_bug.cgi?id=825826
https://fedorahosted.org/rel-eng/ticket/5230