move ssl cipher list from compiletime to context creation time option

More flexible this way... NULL for the new member means use
the ssl library default set of ciphers, so as long as your info
struct is zerod by bss or memset, you don't need to do anything
about this change unless you want to set the cipher list.

Signed-off-by: Andy Green <andy.green@linaro.org>
diff --git a/README.coding b/README.coding
index bb093fb..0231d03 100644
--- a/README.coding
+++ b/README.coding
@@ -209,3 +209,18 @@
 like Linux does.  On those systems you can enable keepalive by a nonzero
 value in ka_time, but the systemwide kernel settings for the time / probes/
 interval are used, regardless of what nonzero value is in ka_time.
+
+Optimizing SSL connections
+--------------------------
+
+There's a member ssl_cipher_list in the lws_context_creation_info struct
+which allows the user code to restrict the possible cipher selection at
+context-creation time.
+
+You might want to look into that to stop the ssl peers selecting a ciher which
+is too computationally expensive.  To use it, point it to a string like
+
+"RC4-MD5:RC4-SHA:AES128-SHA:AES256-SHA:HIGH:!DSS:!aNULL"
+
+if left NULL, then the "DEFAULT" set of ciphers are all possible to select.
+