Improvements for BOA

- Allowed write buffers to become very large in asynnet. Thus in order to allow for the transfer
  of large images. tested ub to 2kx2k, 16MB
- Handle lack of space in the write buffer more gracefully: just skip the image

rwpuffer.h

@@ -16,6 +16,13 @@ typedef struct __RWBuffer *prwBuffer;
  * \return NULL on success, else a pointer to t a new rwPuffer
  */
 prwBuffer MakeRWPuffer(int size);
+/**
+ * \brief create a RW buffer which can grow.
+ * \param size The size of the buffer.
+ * \param maxSize The maximum size of the buffer. 
+ * \return NULL on success, else a pointer to t a new rwPuffer
+ */
+prwBuffer MakeBigRWPuffer(int size, int maxSize);
 /**
  * \brief delete a rw buffer.
  * \param self The rwPuffer to delete.
@@ -29,6 +36,14 @@ void KillRWBuffer(prwBuffer self);
  * \return 1 on success, 0 on failure
  */
 int StoreRWBuffer(prwBuffer self, void *data, int count);
+/**
+ * \brief Test if the data can be stored in the rwBuffer
+ * \param self The rw buffer to store the data in
+ * \param data pointer to the data to store
+ * \param count The number of bytes to store
+ * \return 1 when OK, 0 when buffer full
+ */
+int CanStoreRWBuffer(prwBuffer self, void *data, int count);
 /**
  * \brief Get a pointer to the current buffer data
  * \param self the buffer to get the data from