sudo security, bug fix, and enhancement update

[1.8.6p7-20]

• RHEL 7.3 erratum
  • fixed visudo’s -q flag
    Resolves: rhbz#1350828
    [1.8.6p7-19]
• RHEL 7.3 erratum
  • removed INPUTRC from env_keep to prevent a potential info leak
    Resolves: rhbz#1340700
    [1.8.6p7-18]
• RHEL 7.3 erratum
  • removed requiretty flag from the default sudoers policy
  • backported pam_service and pam_login_service defaults options
  • implemented netgroup_tuple defaults option for changing netgroup
    processing semantics
  • fixed user matching logic in the LDAP nss backend
  • don’t allow visudo to accept an invalid sudoers file
  • fixed a bug causing that non-root users can list privileges of
    other users
  • modified digest check documentation to mention the raciness of
    the checking mechanism
    Resolves: rhbz#1196451
    Resolves: rhbz#1247230
    Resolves: rhbz#1334331
    Resolves: rhbz#1334360
    Resolves: rhbz#1261998
    Resolves: rhbz#1313364
    Resolves: rhbz#1312486
    Resolves: rhbz#1268958
    Resolves: rhbz#1335039
    Resolves: rhbz#1335042
    Resolves: rhbz#1335045
    Resolves: rhbz#1273243
    Resolves: rhbz#1299883