CodeSnip Old Code (SVN)

* Changed character set testing code in several units to use char set helper functions added to UUnicodeHelper.pas instead of testing directly against literal or constant sets. This prevents Delphi 2010 warnings about WideChar being reduced to byte char in set expressions.
* Changed use of UpCase built-in to use ToUpperCase function added to UUnicodeHelper.pas.
* Added various set handling routines along with ToUpperCase function. These mainly call TCharacter methods on Unicode Delphis and have custom implementations on other Delphis.

Modified TAppInfo.GenerateKey to be Unicode compatible: now uses new ASCIIBytesOf routine (added to UUnicodeHelper unit) to ensure program key contains only ASCII characters.

* TUserDBBackup.Backup now uses TBytes version of TChecksum.Calculate to get checksum of a file's contents.
* Changed TUserDBBackup.Restore to work with new TDataStreamString string type used by classes in UDataStreamIO unit.

* Changed TFileUpdater to work with new TDataStreamString string type used by classes in UDataStreamIO unit.
* TFileUpdater now uses TCheckSum.Compare rather than TChecksum.Calculate when checking checksums.

* Added support for Latin1 code page: string definition, code page constant, custom encoding class and Latin1BytesOf helper function.
* Defined TBytes for non-Unicode Delphis.
* Provided BytesOf function for non-Unicode Delphis.

Made TBytes version of TChecksum.Calculate compilable in non-Unicode Delphis as well as Unicode versions.

Modified UDataStreamIO.pas for Unicode compatibility.
* Changed string type read/written to TDataStreamString which is defined as AnsiString on Ansi Delphis and Latin1String on Unicode: i.e. single byte strings on all compilers.
* Provided overloaded write string methods that take Unicode strings and convert to Latin1.
* Provided methods to convert strings to byte arrays for writing.

Amended TCheckSum to be compatible with Unicode Delphis:
* All methods that return string now return AnsiString.
* Checksums are always dealt with as Ansi strings.
* All methods that calculate check sums if strings now take Ansi strings as parameters.
* On Unicode Delphis added new Calculate method that calculates the checksum of a byte array.

Made MD5.pas compatible with Unicode Delphis.
* Changed MD5Update to take a PByteArray as input, instead of PChar.
* Changed MD5String to take an AnsiString as parameter instead of string.
* Changed MD5Print to return an AnsiString instead of a string.

* Switched off support for Vista common dialogs in UCommonDlg.pas for compilers that support these dialogs.
* Added SupportsUseLatestCommonDialogs symbol to CompilerDefines.inc that is defined for compilers where Dialogs.UseLatestCommonDialogs is declared.