[YOCTO #1776] license: manifest and license path

[YOCTO #1776] license: manifest and license path

This is a fairly large commit, so I want to step through some of
what this accomplishes:

1. Additional licenses

I've added/modified/corrected some of the common licenses
within OE-core in prep. for a major license audit. Most of these
are in SPDX format. A few, there is no OSI equivalent.

2. Additional SPDX mappings

I've added some additional SPDX mappings to account for removing
some duplicate licenses. (ie GPL-2 and GPL-2.0 were the same)
I've also remapped a few things to more accurately reflect what
they should be pointing at.

Note: Artistic/LGPL/GPL/MPL. Quite a few LICENSE fields list these
licenses. They make no sense and need auditing. In a future commit
I have some fixes to particularly egregious LICENSE fields, but
a full audit should be done. I've listed to obvious candidates at:

https://wiki.yoctoproject.org/wiki/License_Audit

3. License manifest

We now have a license manifest generation that occurs in rootfs for
everything BUT .deb. This requires the changes Paul Eggleton has
done to rootfs_* particularly the list_installed_packages function.
The manifest is accurate during a parallel bitbake now (Weee!) and
is prime for my planned SPDX format manifest during the next period.

4. License manifest on image.

We also want the ability to add licenses to the image. This
functionality is also in base-files and will be stripped out in my
next commit. The manifest is not added by default and is a two var
setting in license.conf:

If I want *just* the manifest on the image (small) then I set:
COPY_LIC_MANIFEST = "1"

This copies the manifest to:

/usr/share/common-licenses/license.manifest

If I want the actual PKG license text on the image (much larger)
I need to set both both COPY_LIC_MANIFEST and COPY_LIC_DIRS in
license.conf. This will create:

/usr/share/common-licenses/(package name)/(licenses in LIC_SRC_URI)

Word of warning. This can be larger than wanted depending on image
and is probably ripe for linking licenses, but I ran out of time this
week to get that done.

5. Custom License search path.

We now have the ability to add licenses to the build without touching
common-licenses. This is set via license.conf:

LICENSE_PATH += "/path/to/custom/licenses"

You want to make sure the license is unique. license.bbclass picks the
first license it finds.

Signed-off-by: Elizabeth Flanagan <elizabeth.flanagan@intel.com>