Correct three typos in manuals.

crypto/heimdal/appl/login/login.access.5

@@ -31,7 +31,7 @@ or
 .It
 The second field is a comma separated list of users or groups for
 which the current entry applies. NIS netgroups can used (if
-configured) if preceeded by @. The magic string ALL matches all users.
+configured) if preceded by @. The magic string ALL matches all users.
 A group will match if the user is a member of that group, or it is the
 user's primary group.
 .It

crypto/heimdal/kcm/kcm.8

@@ -95,7 +95,7 @@
 is a process based credential cache.
 To use it, set the
 .Ev KRB5CCNAME
-enviroment variable to
+environment variable to
 .Ql KCM: Ns Ar uid
 or add the stanza
 .Bd -literal

crypto/heimdal/kdc/kdc.8

@@ -84,7 +84,7 @@ You might want to turn it off if you have clients
 that don't support pre-authentication.
 Since the version 4 protocol doesn't support any pre-authentication,
 serving version 4 clients is just about the same as not requiring
-pre-athentication.
+pre-authentication.
 The default is to require pre-authentication.
 Adding the require-preauth per principal is a more flexible way of
 handling this.