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!
  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:
========
 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

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[generic]                 4889    4948  98.8% -lh5- 1dab Dec  3 14:28 SetFileSize64/SetFileSize64
[generic]                  541    1240  43.6% -lh5- 476e Dec  3 14:33 SetFileSize64/SetFileSize64.readme
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         2 files    5430    6188  87.8%            Dec  3 21:27