[oe] A new bitbake extension: .bbappend files

[Michael Smith]

Tom Rini wrote:
> It's also needed, in some cases, to lock down your changes via OVERRIDES 
> that will only match what you want to work on.  For example, we're using 
> a snapshot with an older python, so amend.inc in our python directory 
> looks like:
> 
> SRC_URI_append_pn-python-native = 
> "file://python-2.6-r73342.patch;patch=1;pnum=0"
> PARALLEL_MAKE_pn-python-native = ""
> PR_append_pn-python-native .= ".1"
> 
> So that we only change python-native and not all of the other python 
> recipes.

I think you could get the same effect by putting your amend.inc in a 
python-native subdirectory under your overlay recipes/python directory.

Maybe there's some native magic going on that would break that. (I've 
never amended a -native package but I use the same trick for other 
recipes where there are multiple .bb files are in the same OE directory.)

Mike