Allow people to add users with dots in their names.

http://bugs.gentoo.org/22920

--- libmisc/chkname.c
+++ libmisc/chkname.c
@@ -18,7 +18,7 @@
 static int good_name (const char *name)
 {
 	/*
-	 * User/group names must match [a-z_][a-z0-9_-]*
+	 * User/group names must match [a-z_][a-z0-9_-.$]*
 	 */
 	if (!*name || !((*name >= 'a' && *name <= 'z') || *name == '_'))
 		return 0;
@@ -27,6 +27,7 @@
 		if (!((*name >= 'a' && *name <= 'z') ||
 		      (*name >= '0' && *name <= '9') ||
 		      *name == '_' || *name == '-' ||
+		      *name == '.' ||
 		      (*name == '$' && *(name + 1) == '\0')))
 			return 0;
 	}
--- man/useradd.8
+++ man/useradd.8
@@ -128,6 +128,23 @@
 If no options are specified,
 \fBuseradd\fR
 displays the current default values.
+.SH RESTRICTS
+Currently,  the  shadow  suite  enforces  the following restrictions on 
+user names:
+
+.nf
+\- must begin with a lower case letter or underscore
+\- can only contain lower case letters, underscores, and dashes
+\- may end with a dollar sign
+\- regex for these requirements: [a\-z_][a\-z0-9_\-$]*
+.fi
+
+The length of usernames is restricted by glibc (via the UT_NAMESIZE define 
+in the utmp header file).  This may range from 8 characters on older 
+systems to 32 characters on newer systems.
+
+Note Gentoo adds a patch which allows people to create usernames with a 
+dot in them.
 .SH "NOTES"
 .PP
 The system administrator is responsible for placing the default user files in the