Change the filesize of a file, with 64bit support!

SetFileSize File/A,NewSize/A,V=Verbose/S:
  File/A           : The filename whose filesize should be set. If it doesn't exist, it will be created.
  NewSize/A        : The new filesize, with 64bit support!
  Z=FillWithZeros/S: Overwrite the new data with zeros, otherwise data from deleted files could be used!
  V=Verbose/S      : For testing, show "Set filesize to xxx bytes...".
  K/S              : NewSize will be multiplied by 1.000!
  M/S              : NewSize will be multiplied by 1.000.000!
  G/S              : NewSize will be multiplied by 1.000.000.000!
  KB/S             : NewSize will be multiplied by 1024!
  MB/S             : NewSize will be multiplied by 1024*1024!
  GB/S             : NewSize will be multiplied by 1024*1024*1024!

Example:
========
> SetFileSize64 HundertMegaByte 100 MB

Set the filesize of the file "HundertMegaByte" to 100 MB.

> SetFileSize64 HundertTausend 100 K

Set the filesize of the file "HundertTausend" to 100.000 Bytes.


History:
========
 26-May-2020: v1.2
	chg: I'm now using a 10KB buffer for writing the zeros, before I had a 1KB buffer, but this was too slow
	chg: Changed the name of the Z=ZEROING/S option to Z=FillWithZeros/S

 03-Dec-2018: v1.1
	new: Added K/S, M/S, G/S and KB/S, MB/S, GB/S parameters to easily
		 set the filesize to some common values

 PERMSSN    UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[Amiga]                   5861    5917  99.1% -lh5- cf00 May 26  2020 SetFileSize64/SetFileSize64
[Amiga]                    708    1588  44.6% -lh5- 2da0 May  4 21:04 SetFileSize64/SetFileSize64.readme
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         2 files    6569    7505  87.5%            May  5 01:26