RxUnlockLoadFuncs
  adds function to rexx

RxUnlockDropFuncs
  removes functions from rexx (do not use)

RxUnlockDebug( debug )
  debug is 0 or 1
  enables display if internal function calls and results

RxUnlockFiles( filespec [, filespec ..] )
  * filespec may contain wild cards

RxReplaceModule( SourceName, TargetName)
  * may not contain wild cards
  * in opposite to REPMOD.EXE it does NOT search .EXE files or load .DLL files
    to get the fully qualified name. specify the full name yourself.
  * internal work is about
     - if TagetName exists, unlock it and remove any readonly attribute
     - Copy SourceName TargetName

RxBldLevel( filename )
  may return
    '"string"'
    'no signature'
    numerical error code, like 110(error_Open_Failed)

RxMD5( filename [, progressbar] )
  filename may indicate a CDROM drive ('H:')
  progressbar is optional, value '1' enables it, default is disabled
  may return
    32 hexadecimal digits (success)
    'ERROR: read error'
    'ERROR: not CDROM'
    'ERROR: can not open'

RxCRC32( filename [, progressbar] )
  like RxMD5, 8 hexadecimal digits on success

RxFileCompare( filename1, filename2 )
  Returns 1 if files are equal and not error occured, else 0.
  This function does not compare extended attribute data.

RxCpuId( Subfunction )
  * Subfunction '0'
    Returns Family/Model/Stepping and a Vendor string
    example results:
      Intel PIII:  '681 GenuineIntel'
      AMD K6:      '561 AuthenticAMD'
      (first 486): '400 Unknown'
      (386):       '300 Unknown'
  * other subfunctions currently return ''

RxStemSearch3(  searchstring, sourcestemname, targetstemname)
  Use is not recommended, since it is slower than doing the
  query in native rexx code.

RxRandomize
  Initialises the built-in random number generator with a random value
  obtained from the system timer.

RxRandom( Range )
  The result is a random number within the range 0 <= X < Range.
  The quality of this function is for selecting pieces of music, 
  not for cryptographic use!

RxExecutableType( FileName )
  Returns 'NE'/'LX'/'PE'/'MZ'/etc... from executable header of FileName,
  else an error message starting with 'Error: '.
  