rewrote forward API to use cached parameter pushing instead of immediate pushing

removed copy back cruft since it's no longer needed
removed PushCells() from API requirements, not needed
adjusted documentation and added TODO list to ForwardSys.cpp
various internal improvements

--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%40188

sourcepawn/include/sp_vm_api.h

@@ -216,10 +216,10 @@ namespace SourcePawn
 		 * Converts a physical string to a local address.
 		 *
 		 * @param local_addr	Local address in plugin.
-		 * @param chars			Number of chars to write, including NULL terminator.
+		 * @param bytes			Number of chars to write, including NULL terminator.
 		 * @param source		Source string to copy.
 		 */
-		virtual int StringToLocal(cell_t local_addr, size_t chars, const char *source) =0;
+		virtual int StringToLocal(cell_t local_addr, size_t bytes, const char *source) =0;
 
 		/**
 		* Converts a physical UTF-8 string to a local address.
@@ -229,9 +229,12 @@ namespace SourcePawn
 		* @param local_addr		Local address in plugin.
 		* @param maxbytes		Number of bytes to write, including NULL terminator.
 		* @param source			Source string to copy.
-		* @param wrtnbytes		Optionally filled with the number of written bytes.
+		 * @param wrtnbytes		Optionally set to the number of actual bytes written.
 		*/
-		virtual int StringToLocalUTF8(cell_t local_addr, size_t maxbytes, const char *source, size_t *wrtnbytes) =0;
+		virtual int StringToLocalUTF8(cell_t local_addr, 
+									  size_t maxbytes, 
+									  const char *source, 
+									  size_t *wrtnbytes) =0;
 
 		/**
 		 * Pushes a cell onto the stack.  Increases the parameter count by one.