[oe] RFC: Rename MACHINE_TASK_PROVIDER to DEFAULT_TASK_PROVIDER

[Rod Whitby]

> <rwhitby> so in my mokoslug distro, I set MACHINE_TASK_PROVIDER to task-boot or task-base, depending on flash size.
> <rwhitby> what is MACHINE_TASK_PROVIDER really meant to be used for?
> <koen> to distinguish between task-bootstrap and task-base
> <rwhitby> does task-bootstrap still exist?
> <koen> rwhitby: I hope not
> <rwhitby> koen: so MACHINE_TASK_PROVIDER has no current reason for existence then?
> <rwhitby> (and no definition of what it should be used for if it did have a current reason for existence)
> <koen> rwhitby: not that I know off, but your task-boot suggestion would make sense
> <rwhitby> koen: So it really should now be called something like BOOTSTRAP_IMAGE_FOUNDATION_TASK or something?
> <rwhitby> (since it doesn't have anything to do with MACHINEs)
> <koen> nor with BOOTSTRAP
> <koen> something like DEFAULT_TASK_PROVIDER?
> <rwhitby> yep, DEFAULT_TASK_PROVIDER floats my boat.
> <koen> do you want to write an RFC for that?

The proposal is to replace MACHINE_TASK_PROVIDER with
DEFAULT_TASK_PROVIDER throughout OE, and encourage all image-foo.bb
maintainers to base their image on DEFAULT_TASK_PROVIDER (which can be
set to task-boot, or task-base, or perhaps some other distro-specific
single task-foo value), plus other image-specific stuff.

Comments?  Objections?

BTW, task-bootstrap existence is as follows:

> ./conf/distro/generic.conf:PREFERRED_PROVIDER_task-bootstrap = "task-bootstrap"
> ./conf/distro/include/oplinux.inc:PREFERRED_PROVIDER_task-bootstrap = "task-base"
> ./conf/distro/angstrom-2007.1.conf:PREFERRED_PROVIDER_task-bootstrap = "task-bootstrap"
> ./conf/distro/jlime-donkey.conf:PREFERRED_PROVIDER_task-bootstrap = "task-bootstrap"
> ./conf/distro/openprotium.conf:#PREFERRED_PROVIDER_task-bootstrap = "task-bootstrap"
> ./conf/machine/gumstix.conf:PREFERRED_VERSION_task-bootstrap = "1.0unionroot"
> ./packages/obsolete/tasks/task-bootstrap-unionroot.bb:PROVIDES = "task-bootstrap"
> ./packages/obsolete/tasks/task-bootstrap-unionroot.bb:RPROVIDES = "task-bootstrap"
> ./packages/obsolete/tasks/task-bootstrap-unionroot.bb:require task-bootstrap.inc
> ./packages/obsolete/tasks/task-bootstrap.bb:require task-bootstrap.inc
> ./packages/images/jlime-opie.bb:DEPENDS = "task-bootstrap task-opie"
> ./packages/images/jlime-opie.bb:INSTALL_PACKAGES = "task-bootstrap task-opie-base task-opie-base-applets \
> ./removal.txt:Package Name:   task-bootstrap*

-- Rod