MFC r328160:

MFC r328160:
  Add to bsnmpd(1) ability to specify multiple community strings with
  different access rights.

  By default there are two community strings with index 1 and 2, one for
  read-only access and second for read-write access:

    begemotSnmpdCommunityString.0.1 = $(read)
    begemotSnmpdCommunityString.0.2 = $(write)

  Now it is possible to define additional community strings using different
  indexes:

    begemotSnmpdCommunityString.0.3 = "SomeString1"
    begemotSnmpdCommunityPermission.0.3 = 1
    begemotSnmpdCommunityString.0.4 = "SomeString2"
    begemotSnmpdCommunityPermission.0.4 = 2
    begemotSnmpdCommunityString.0.5 = "SomeString3"
    begemotSnmpdCommunityString.0.6 = "SomeString4"

  New attribute begemotSnmpdCommunityPermission can be used to specify access
  rights: 1 means "read-only" access, 2 means "read-write" access. If
  attribute is not specified for some index this means "read-only" rights.

  Community strings must be unique, i.e. must not be the same for different
  indexes.

  Obtained from:	Yandex LLC
  Sponsored by:		Yandex LLC
  Differential Revision:	https://reviews.freebsd.org/D13785

MFC r328171:
  Rename "index" variable to "idx" since gcc complains that it shadows
  index(3) function declaration.