(Merge OM mtn modification back into mainline)

(Merge OM mtn modification back into mainline)
Integrate mainstream to build meta-toolchain-openmoko
packages/meta/meta-toolchain-openmoko.bb: will install
task-openmoko-toolchain-{target,host}
task-openmoko-toolchain-target: specific to target arch.
task-openmoko-toolchain-host: for host and all, such as
openmoko-sample2-src
moko-autorev.inc, sane-srcrevs.inc: add SRCREV_pn-openmoko-toolchain-scripts
openmoko-toolchain-scripts_svn.bb: will not install sample code now.
openmoko-sample2_svn.bb: update PACKAGE_ARCH_${PN}-src to be used by
ipkg-sdk.conf