fix #1843: remove static fields from AuthErrorDialogFragment
Merge pull request #1845 from wordpress-mobile/issue/1843-autherrordialog-crash

fix #1843: remove static fields from AuthErrorDialogFragment
Add history stack class for more reliable read/write of tag preview history
Merge pull request #1847 from wordpress-mobile/issue/1841-reader-class-cast-exception

issue/1841-reader-class-cast-exception
Merge remote-tracking branch 'origin/hotfix/3.1.2' into release/3.2