enhancement request: memory usage in real values

Hi,

In case someone is interested, I created a patch for this:

- renamed function get_mem_percent to get_percent

- created new function get_percent
	-> this searches for the 3 values for used, total and percent

- renamed function do_memory_rrd_update to do_memory_rrd_update_pct

- created new function do_memory_rrd_update
	-> the rrd created start with absolute-memory and contains the used and 
total values


Stef