doc: avoid regex ambiguity in chmod mode description

* man/chmod.x: s/[+-=]/[-+=]/
* doc/perm.texi (Symbolic Modes): Likewise.
* THANKS.in: Remove patch owner.
Fixes http://bugs.gnu.org/17041

THANKS.in

@@ -179,7 +179,6 @@ Doug McLaren                        dougmc@comco.com
 Dragos Harabor                      dharabor@us.oracle.com
 Duncan Roe                          duncanr@optimation.com.au
 Edward Schwartz                     edmcman@cmu.edu
-Edward Welbourne                    eddy@opera.com
 Edzer Pebesma                       Edzer.Pebesma@rivm.nl
 Egmont Koblinger                    egmont@uhulinux.hu
 Eirik Fuller                        eirik@hackrat.com

doc/perm.texi

@@ -148,7 +148,7 @@ their previous values, and perhaps on the current @code{umask} as well
 The format of symbolic modes is:
 
 @example
-@r{[}ugoa@dots{}@r{][}+-=@r{]}@var{perms}@dots{}@r{[},@dots{}@r{]}
+@r{[}ugoa@dots{}@r{][}-+=@r{]}@var{perms}@dots{}@r{[},@dots{}@r{]}
 @end example
 
 @noindent

man/chmod.x

@@ -16,7 +16,7 @@ which can be either a symbolic representation of changes to make, or
 an octal number representing the bit pattern for the new mode bits.
 .PP
 The format of a symbolic mode is [\c
-\fBugoa\fP.\|.\|.][[\fB+-=\fP][\fIperms\fP.\|.\|.].\|.\|.],
+\fBugoa\fP.\|.\|.][[\fB-+=\fP][\fIperms\fP.\|.\|.].\|.\|.],
 where
 .I "perms"
 is either zero or more letters from the set