cookerdata: Set TOPDIR when using bblayers.conf

By definition, bblayers.conf is at the top of the build tree. We'd like
to support running bitbake anywhere within that build tree but TOPDIR
gets set to wherever cwd is. Change the code to reset TOPDIR
to the top of the build directory.

This shouldn't break anything but does make the system more usable.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
cookerdata: Allow bblayers.conf to be found using BBPATH

It should be possible to run a build anywhere on the filesystem and have
bitbake find the correct build directory if its set somehow. The BBPATH
variable makes perfect sense for this usage. Therefore use any available
value of BBPATH to search for conf/bblayers.conf before walking the parent
directory structure.

This restores the option of being able to run bitbake from anywhere if
the user has set things up to operate in that environment.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
server/xmlrpc: Increase timeout to 60s

This is a better value that the earlier infinite timeout yet still
allows for servers with high loads. It does mean the bitbake process
can hang at exit for the timeout period but that should never happen
and only happened for me in some test cases which wouldn't happen
in normal use.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>