Legacy staging

The term "legacy staging" refers to recipes or classes which have a do_stage function for populating the sysroot directories that we use for building, rather than having a do_install that works, along with post install functions to mangle the contents as needed.

In OpenEmbedded-Classic, legacy staging was deprecated but still supported; but with OE-Core, BitBake will error out during parse if it finds a do_stage function defined in any recipe, so when migrating a recipe you will need to translate this if present.

Steps for moving script code in the do_stage function to the do_install function:

1. Move the lines in do_stage to do_install, deleting anything that is already handled in the existing do_install
2. Replace STAGING_BINDIR with ${D}${bindir}
3. Replace STAGING_INCDIR with ${D}${includedir}
4. Replace STAGING_LIBDIR with ${D}${libdir}
5. Replace STAGING_DATADIR with ${D}${datadir}