Add device type constants to the device type combobox's store

This can we cand get rid of many mappings and complex code doing comparisons
between translated strings.
Only save changes if there are any changes to be saved

It's not always necessary to save changes in mountpoint's configuration when
switching from one selector to the other. If user clicks the Update Settings
button the same code runs so we can skip the extra call in following selector
change.
Don't rely on the ordering of autopart types in the combobox

Relying on autopart types' ordering matching the pykickstart constants is very
fragile. Let's use a ComboBox with a proper model defined by us and put those
constants to the model instead.
Split long label's string into two lines
Move a few constants and mappings to the storage_utils module

All those constants and mappings are not GUI-specific and thus may live in a
place where they can be used from non-GUI code as well. Also the Custom spoke's
source file is long enough even without them.
Add DEVICE_TYPE_DISK's text description to the mapping

Otherwise user's won't see the text description or a traceback will appear.
Give names to some magic tuples, make them reusable and reuse them
No need to call bool() on a boolean expression result
Only save changes if needed when adding mountpoint

If there are no changes to be saved, it's not necessary to call the code saving
them. Also we should only reset the back_already_clicked flag if some mountpoint
was actually added.
Check Update Settings button sensitivity when saving changes in one place

There's no need to have this code in multiple places. The same applies to
resetting the back_already_clicked flag. Also it's nice to have all the
short-circuiting code at the beginning of the function.
Separate code for finding item in containers combo and processing it

Also prevent traceback with found being used before being assigned to if there
is no matching item in the combobox.
Only run dialogs in the enlightbox context

All the other code can be run outside of those blocks possibly shortening the
time between lightbox being shown and dialogs appearing.
Disable a false positive from pylint
Make sure the idx variable is used instead of the old found variable
Use more wildcards in the tests dist_ variable

It was getting kind of crowded, and there's no reason to have to change
Makefile.am for every new pylint module or glade check.
Ignore more informational messages printed by pylint pragmas

Also, we can ignore I0011 in the --disable list instead of looking for
it with grep.
Remove a whole bunch of pylint false positives

The latest python-astroid finds every GObject method we use except for
get_property and set_property, so clean out pylint-false-positives and
remove some disable pragmas for emit and connect.
Set the selinux state from the command line (#784828)

It turns out that we forgot to actually do anything with this command
line option. Change SELINUX_DEFAULT to -1 so that we can tell the
difference between nothing requested and SELINUX_ENFORCING explicitly
requested, so that we don't override kickstart settings in the former
case.
Add an option to copy translation files to an updates.img
New version - 21.33