createBufferedMatrix: createBufferedMatrix
In BufferedMatrix: A matrix data storage object held in temporary files

Creates a Buffered Matrix object

1	createBufferedMatrix(rows, cols=0, bufferrows=1, buffercols=1,prefix="BM",directory=getwd())

`rows`	Number of rows in the matrix
`cols`	Initial number of coulmns in the matrix
`bufferrows`	number of rows to be buffered if the row buffer is activated
`buffercols`	number of columns to be buffered
`prefix`	String to be used as start of name for any temporary files
`directory`	path to directory where temporary files should be stored