cleaned up issues with Daniel's code

There were a lot of style things and a misunderstanding of the protocol
between the cape and the BBB.
diff --git a/bbb_cape/src/cape/cape.gyp b/bbb_cape/src/cape/cape.gyp
index e9d34ef..91ec298 100644
--- a/bbb_cape/src/cape/cape.gyp
+++ b/bbb_cape/src/cape/cape.gyp
@@ -1,4 +1,9 @@
 {
+  'target_defaults': {
+    'include_dirs': [
+      '..',
+    ],
+  },
   'targets': [
     {
       'target_name': 'cows',
@@ -7,5 +12,9 @@
         'cows.c',
       ],
     },
+    {
+      'target_name': 'data_struct',
+      'type': 'static_library',
+    },
   ],
 }
diff --git a/bbb_cape/src/cape/cows.c b/bbb_cape/src/cape/cows.c
index 396889c..16ed1fc 100644
--- a/bbb_cape/src/cape/cows.c
+++ b/bbb_cape/src/cape/cows.c
@@ -1,4 +1,4 @@
-#include "cows.h"
+#include "cape/cows.h"
 
 #include <limits.h>
 
diff --git a/bbb_cape/src/cape/data_struct.h b/bbb_cape/src/cape/data_struct.h
index 95992b9..797648f 100644
--- a/bbb_cape/src/cape/data_struct.h
+++ b/bbb_cape/src/cape/data_struct.h
@@ -60,6 +60,7 @@
 
 // The number of bytes that we actually send (so it stays consistent) (including
 // the byte-stuffing overhead and the CRC on the end).
+// This will always be a multiple of 4.
 #define DATA_STRUCT_SEND_SIZE 200
 
 #ifdef __cplusplus