documentation: Makefile, dev-manual - edits to patching kernel

Made some general edits to the new "Patching the Kernel" section.
Also had to remove a couple of images no longer used in the section
from the Makefile "TARFILES" variable.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: dev-manual - Typo fixed.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - LICENSE_PATH not LICENSE_DIR.

Fixes [YOCTO_#3118]

LICENSE_PATH is the correct variable to use for 1.3 - see:

https://bugzilla.yoctoproject.org/show_bug.cgi?id=3118

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - Variable descriptions edited.

Adjust the descriptions so that it is clearer that these are specific
to a machine and should appear in the machine's .conf file, and are
intended to affect the image contents, not the dependencies of a
specific package. Also change the examples so that they demonstrate more
realistic usage scenarios for these variables.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - MACHINE definition extended.

Extend the description of the MACHINE variable so that it mentions that
this points to a .conf file under conf/machine.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - New PACKAGECONFIG glossary entry.

Add a description of the PACKAGECONFIG variable to the variable
glossary.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - DISTRO description extended.

Extend the description of the DISTRO variable so that it mentions that
this points to a .conf file under conf/distro and mentions what happens
if the value is left blank.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - New backfill variables and section.

Document DISTRO_FEATURES_BACKFILL and MACHINE_FEATURES_BACKFILL. We may
wish to expand upon this in future, but at least this explains what
these variables are for and how to use them.

Also add a link from the DISTRO_FEATURES entry to the section that lists
valid DISTRO_FEATURES items.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - Edits to fix default description

* Use correct/up-to-date names of package systems
* SUMMARY does not default to the value of DESCRIPTION, it's the other
  way around (although the logic may be improved in future so that this
  is the effect).

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - change support to opkg from ipkg

We haven't supported ipkg for some time now - it was replaced by opkg
(whilst still using the ipk package format).

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - wording changes

Some wording changes from "packages" to "recipe" as appropriate
in some of the variable glossary entries.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
documentation: poky-ref-manual - Updates to the poky structure

* Add meta-yocto, meta-yocto-bsp and meta-hob
* Remove meta-rt - this was merged into OE-Core (meta)
* Remove meta-demoapps - this was dropped

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>