REORG: include: move cfgparse.h to haproxy/cfgparse.h

There's no point splitting the file in two since only cfgparse uses the
types defined there. A few call places were updated and cleaned up. All
of them were in C files which register keywords.

There is nothing left in common/ now so this directory must not be used
anymore.
diff --git a/src/cache.c b/src/cache.c
index ba96ede..56368f3 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -12,6 +12,7 @@
 
 #include <haproxy/action-t.h>
 #include <haproxy/api.h>
+#include <haproxy/cfgparse.h>
 #include <haproxy/channel.h>
 #include <haproxy/cli.h>
 #include <haproxy/filters.h>
@@ -27,7 +28,6 @@
 #include <import/sha1.h>
 
 
-#include <common/cfgparse.h>
 #include <haproxy/hash.h>
 #include <haproxy/htx.h>
 #include <haproxy/net_helper.h>