Moved from lib/wic/utils/ to lib/wic as this is a core module.

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>

All wic exceptions are now inherited from new base exception
class WicError. It makes them easy to maintain and catch.

Processing of exceptions is done this way:
    Known wic exceptions cause wic to print error message to stdout.
    Unknown exceptions are not catched anymore and produce standard
    python traceback.

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

To support yocto on systems with python3 as default version, scripts
should use /usr/bin/env python in the shebang, as this allows the use of
a fake env to mimic python2 as default version.

This patch simply replaces occurrences of #!/usr/bin/python with
 #!/usr/bin/env python and was done with this oneliner:

     git grep -lE '^#!/usr/bin/python' | xargs \
         sed -i 's|/usr/bin/python|/usr/bin/env python|'

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

As well as any other stray instances of mic in the codebase that can
be removed.

We don't really need to carry around legacy naming, and the history is
in git.

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