Add some buffer management routines

libXmd/include/Xmd/Buffer.h

@@ -0,0 +1,25 @@
+#ifndef _XmdBuffer_h
+#define _XmdBuffer_h
+
+#include <stddef.h>
+
+/* Buffer is a struct that keeps track of a variable length array of data. It
+   is like a piggy bank, you can add stuff to it and then break it to get access
+   to all the things you put in. It is intended to be used for reading in
+   variable length strings and files. */
+typedef struct _XmdBuffer XmdBuffer;
+
+/* XmdBufferNew creates a new buffer with the specified element size. */
+XmdBuffer *XmdBufferNew (size_t element);
+
+/* XmdBufferPush adds a new element to the buffer. */
+void XmdBufferPush (XmdBuffer *buffer, void *element);
+
+/* XmdBufferBreak frees the buffer without freeing its data. Its data is
+   returned and must be freed manually at some point. */
+void *XmdBufferBreak (XmdBuffer *buffer);
+
+/* XmdBufferFree frees the buffer and any data associated with it. */
+void XmdBufferFree (XmdBuffer *buffer);
+
+#endif