target: add symbols for i386/x86_64 cpu features

Selecting the target subarchitecture variant automatically selects the
appropriated set of features.

[thomas.petazzoni@free-electrons.com:
  removed depends on inside hidden options, not needed.
  removed SSE41/SSE42 options, not used.]

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
libevas: refactor *_CONF_OPT assignment with cpu-feature options

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
sdl_gfx: refactor *_CONF_OPT assignment with cpu-feature options

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
sdl_sound: refactor *_CONF_OPT assignment with cpu-feature options

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
opencv: bump to version 2.4.2

Update Config.in and .mk according to the new features.

Remove the patch handling build with uclibc without long double support,
which seems not necessary anymore.

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
opencv: get rid of unused SSE41 and SSE42 options

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Samuel Martin <s.martin49@gmail.com>
legal-info: infrastructure to collect legally-relevant material

This allows to automatically collect material that may be needed to comply with
the license of packages that Buildroot prepares for the target device.

The core of the implementation is made by the following parts:
 - in package/pkg-utils.mk some helper functions are defined for common actions
   such as generating a warning, producing info about a package etc;
 - in package/pkg-gentargets.mk, within the GENTARGETS framework, a new
   <PKG>-legal-info target produces all the info for a given package;
 - Makefile implements the top-level targets:
   - legal-info-prepare creates the output directory and produces legal info
     about Buildroot itself and the toolchain, which mostly means just warning
     the user that this is not implemented;
   - legal-info, the only target that is supposed to be used directly, depends
     on all of the above and finishes things by producing the README files from
     the various pieces.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
gettext: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
netkitbase: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
netkittelnet: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
newt: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
ttcp: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
vpnc: warn that legal-info is not implemented

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
manual: document usage of the legal-info feature

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
manual: add advice about GPL compliance for Buildroot

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
linux: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
m4: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
mpc: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
fakeroot: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
bzip2: define license

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>