DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments

Some of the Lua doc and a few places still used "Haproxy" or "HAproxy".
There was even one "HA proxy". A few of them were in an example of VTest
output, indicating that VTest ought to be fixed as well. No big deal but
better address all the remaining ones so that these inconsistencies stop
spreading around.
diff --git a/doc/SPOE.txt b/doc/SPOE.txt
index 2ed7878..ba7aca0 100644
--- a/doc/SPOE.txt
+++ b/doc/SPOE.txt
@@ -753,7 +753,7 @@
 
   * pipelining: This is the ability for a peer to decouple NOTIFY and ACK
                 frames. This is a symmectical capability. To be used, it must
-                be supported by HAproxy and agents. Unlike HTTP pipelining, the
+                be supported by HAProxy and agents. Unlike HTTP pipelining, the
                 ACK frames can be send in any order, but always on the same TCP
                 connection used for the corresponding NOTIFY frame.