adding a --all switch to seinfo
adding a --all switch to seinfo

There are 3 major changes in this commit:

1/ Setting the default values to None instead of "". Indeed, when --all is
   passed to the command line, default values are set to "" making the
   'if insinstance(xxx, str)' being True, and thus the script takes the wrong
   branch.
2/ if/elif/else have been replaced by if/else structure, to enable selection of
   multiple switches. Selected component queries are stacked and displayed at
   the end
3/ like the original seinfo, we append some descriptions string (info: count +
   indented results) to the output

TresysTechnology/setools,TresysTechnology/setools,TresysTechnology/setools,TresysTechnology/setools