wizard: use a tab for Advanced opts instead of an expander

GtkExpander containing wrapped labels  breaks GTK3's algorithm computing
the window size when expanding/folding.

A tab page seems to be more modern approach which does not causes any
problems.

The tab pages are filled with GtkScrolledWindow in order to prevent
enlarging the configuration window behind screen limits.

The worfklow window also uses tab pages but on the left side because
two vertical tab page lines are strange.

Resolves rhbz#974746

Signed-off-by: Jakub Filak <jfilak@redhat.com>
bugzilla: show description for all configuration options

The wizard shows note-html tag in the configuration window. description
tag seems to be useless.

Resolves rhbz#1111729

Signed-off-by: Jakub Filak <jfilak@redhat.com>
wizard: Do not highlight sensitive words in user's comment

Resolves rhbz#1111734

Signed-off-by: Jakub Filak <jfilak@redhat.com>
Merge pull request #265 from abrt/ux_improvements_to_wizard

UX improvements to Wizard