buildbot: added builders for Helena at DTU

We build the toolchain using build.sh and then focus on testing platin+aiT.
Merge pull request #4 from alexjordan/buildbot-dtu

buildbot: added builders for Helena at DTU
buildbot: aegean and (future) codebases support

Using codebases allows the use of multiple source repos in a single builder to
work with incoming changes. This requires a newer buildmaster than currently
available at vmars, so everything is commented out for now.
Merge pull request #6 from alexjordan/buildbot-dtu

buildbot: aegean and (future) codebases support
buildbot: update w.r.t version

* codebases stay commented out
singlepath demo Makefile update
build.sh: fixed llvm check-all with ninja
build.sh: fixed -a build, renamed to -o
build.sh: omit benchmarks build by default

To be friendlier to new users of Patmos, build.sh does not build bench by
default (takes forever):
 * Developers are considered smart enough to create a build.cfg and change this
   behavior if required.

Finally, the -a (all) option now really does what you would expect and builds
$ALLTARGETS.