Upversioned the C source tree to '0.0.7-SNAPSHOT', but proposing to start experimental

work towards 0.1.0 in separate source trees.

src/c/memory/cursor.c

@@ -0,0 +1,9 @@
+/*
+ * a cursor is a cons-space object which holds:
+ * 1. a pointer to a vector (i.e. a vector-space object which holds an
+ *    array of `cons_pointer`);
+ * 2. an integer offset into that array.
+ *
+ * this provides a mechanism for iterating through vectors (actually, in
+ * either direction)
+ */