Useful Dll for Inno Setup users

[peterf1999]

Changes:

• Renamed 'CheckFileSHA1' function to 'CheckFileHash'.
• function prototype changes.
• Added support for MD5, SHA256(SHA-2) hash algorithms.

const
  DCP_MD5 = 1;
  DCP_SHA1 = 2;
  DCP_SHA256 = 4; // SHA-2

Type
THashProgress = function(OverallProgress,FileProgress: Integer): Boolean;

function CheckFileHash(const Filename,HashHex: PAnsichar; PctOfTotal: integer; callback: THashProgress; DCP_Hash: integer): integer; external 'CheckFileHash@files:Isab.dll stdcall delayload';

Function return codes:

0: All OK.
-1: Hash check aborted.
-2: File hash does not match.
-3: Source File not found.
-4: Bad flag argument.