wic: Make exec_cmd() error out instead of warn

The reason exec_cmd() warns but doesn't error out (broken parted)
doesn't really make sense, since the parted invocations don't even use
exec_cmd().  It really should just fail since by not doing so it's
actually enabling invalid images in some cases.

Also, since the return code is now always zero, there's no point in
having a return code, so remove it.  This represents a change in the
API, so we also need to update all callers.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove unused custom commands

installer, repo, desktop-related stuff

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove packaging, config commands

Remove commands related to repos, packaging, configuration

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove mic bootstrap

packaging bootstrap, not needed

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove mic chroot

mic chroot allows users to chroot into an existing mic image and isn't
used by wic, so remove it.

Removing chroot.py leads in turn to various plugin-loading failures
for a number of plugins that wic doesn't use either, so remove those
as well.

The existing source plugins refer to chroot but don't use it, so fix
those up.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove rt_util

More package-related stuff we don't need.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove mic package managers

wic doesn't use the yum or zypp package managers, remove them.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove bmap support

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove fiemap support

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove grabber implementation

wic doesn't need to grab any urls, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove proxy support

wic doesn't use proxy support, so remove it.

Also remove anything related to proxies in misc and conf, and while
we're at it, remove all the obviously unneeded code from those files -
it's easier to just remove it than to figure out the callchain to the
proxy code usages.

Basically the extra stuff relates to packaging, images, and config
files we don't use.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove rpmmisc

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove unused fs_related code

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove unused misc code

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove 3rdparty/urlgrabber

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove unused 3rdparty/commands

wic doesn't use anything but partition and bootloader, so remove the
rest.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove gpt_parser

wic doesn't currently use it, so remove.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Remove unused plugin and error code

wic doesn't use it, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Clean up BaseImageCreator

wic doesn't use a lot of BaseImageCreator, so remove it.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
wic: Clean up DirectImageCreator

Remove what wic doesn't use from DirectImageCreator.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>