Change 'To run' to 'To use' in all README.md files

As in:

    sgit -e 's/# To run/# To use/g' '*README.md'

This makes consistent the message for how to use the program. 'How to
use' was chosen because one can run a program just by doing './foo' but
that doesn't imply that's how to use it but the purpose of the section
is how to use it.

2014/birken/README.md

@@ -14,7 +14,7 @@ Alexander Prishchepov\
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog < some_secret_or_something
@@ -71,7 +71,7 @@ a client-side downloader.  The hidden transmitted data cannot be reconstructed
 or even detected from the binary content of the traffic between the client and
 the server.
 
-## To run web server
+## To use web server
 
 ```sh
 ./prog < secret_file_to_be_downloaded
@@ -83,7 +83,7 @@ Try using the program's source code as the secret file:
 ./prog < prog.c
 ```
 
-## To run client-side downloader
+## To use client-side downloader
 
 ```sh
 ./prog http://host[:port]