Iterators now return views, not lists in python3. Where we need
lists, handle this explicitly.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

This sets the scene for removing the default False for expansion
from getVarFlag. This would later allow True to become the default.

On the most part this is an automatic translation with:

sed -e 's:\(\.getVarFlag([^,()]*, [^,()]*\)):\1, True):g'  -i `grep -ril getVar *`

In this case, the default was False, but True was used since in most
cases here expansion would be expected.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Since tasks were renamed to packagegroups some time ago, this variable
name implies that its usage is necessarily related to them which is not
the case. Rename the variable to more closely represent what it does
(whilst still providing backwards-compatibility with a warning for
PACKAGE_GROUP).

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

This includes some utility functions for dealing with groups of packages
defined in the metadata.  Metadata syntax:

    PACKAGE_GROUP_<group> = "<list of packages>"

If the packages in the group are optional:

    PACKAGE_GROUP_<group>[optional] = "1"

Signed-off-by: Chris Larson <chris_larson@mentor.com>