fix improper use of whitespace in README.md files

The use of the markdown trailing whitespace to indicate
line break should NOT be done when the following line is empty.

This removes such improper use of whitespace in README.md files.

2012/hou/README.md

@@ -2,7 +2,7 @@
 
 Qiming Hou  
 <hqm03ster@gmail.com>  
-<http://www.houqiming.net>  
+<http://www.houqiming.net>
 
 ## To build:
 
@@ -75,7 +75,7 @@ the regular expression would be replaced by the format string. In case of a
 conflict, rules appearing earlier would take precedence. One can refer to the
 original text in the format string using `%s`. Other `%` characters in the
 format string must be escaped with another `%`. The space character can be used
-in the regular expression by escaping it with `[]` or `""`. 
+in the regular expression by escaping it with `[]` or `""`.
 
 The following regular expression operators are supported: