packaged-staging.bbclass: Sync with Poky for a number of updates. In summary: Support...

packaged-staging.bbclass: Sync with Poky for a number of updates. In summary: Support using opkg, ipkg and an internal shell script version of ipkg as the package manager allowing removal of a large number of build dependencies. Correctly install packages into staging creating the .list and .control files. Remove accidental install outside the locking in the build package function. Correctly handle error codes in the postamble function. Add code to work correctly with the whitelist stamp policy in bitbake.