Start writing a how to review doc

doc/HACKING/CodingStandards.txt

@@ -141,6 +141,9 @@ sure that we worked on MSVC6.
 We don't use strcat or strcpy or sprintf of any of those notoriously broken
 old C functions.  Use strlcat, strlcpy, or tor_snprintf/tor_asprintf instead.
 
+We don't call memcmp() directly.  Use fast_memeq(), fast_memneq(),
+tor_memeq(), or tor_memneq() for most purposes.
+
 Functions not to write
 ~~~~~~~~~~~~~~~~~~~~~~
 

doc/include.am

@@ -43,6 +43,7 @@ EXTRA_DIST+= doc/asciidoc-helper.sh			\
 	     doc/HACKING/CodingStandards.txt			\
 	     doc/HACKING/GettingStarted.txt			\
 	     doc/HACKING/HelpfulTools.txt			\
+	     doc/HACKING/HowToReview.txt 			\
 	     doc/HACKING/ReleasingTor.txt                       \
 	     doc/HACKING/WritingTests.txt