Update StrWrap routines to take non -ve int params

StrWrap was accepting Integer maximum line lengths and indents, which
makes no sense. Unsurprisingly the routine was failing tests that passed
negative margin and maximum lengths.

So MaxLineLen and Margin parameters were changed from Integer to Word.

Author: delphidabbler

Src/UStrUtils.pas

@@ -228,15 +228,15 @@ function StrSplit(const Str: UnicodeString; const Delim: UnicodeString;
 ///  offsets each line using spaces to form a left margin of size given by
 ///  Margin.</summary>
 ///  <remarks>Output lines are separated by CRLF.</remarks>
-function StrWrap(const Str: UnicodeString; const MaxLen, Margin: Integer):
+function StrWrap(const Str: UnicodeString; const MaxLen, Margin: UInt16):
   UnicodeString; overload;
 
 ///  <summary>Word wraps each paragraph of text in Paras so that each line of a
 ///  paragraph has lines of maximum length MaxLineLen and is offset by the
 ///  number of spaces gvien by Margin. Blanks lines are used to separate
 ///  output paragraphs iff SeparateParas is true.</summary>
 ///  <remarks>Output lines are separated by CRLF.</remarks>
-function StrWrap(const Paras: TStrings; const MaxLineLen, Margin: Integer;
+function StrWrap(const Paras: TStrings; const MaxLineLen, Margin: UInt16;
   const SeparateParas: Boolean): UnicodeString; overload;
 
 ///  <summary>Checks in string Str forms a valid sentence and, if not, adds a
@@ -773,7 +773,7 @@ function StrWindowsLineBreaks(const Str: UnicodeString): UnicodeString;
   Result := StrReplace(Result, LF, CRLF);
 end;
 
-function StrWrap(const Str: UnicodeString; const MaxLen, Margin: Integer):
+function StrWrap(const Str: UnicodeString; const MaxLen, Margin: UInt16):
   UnicodeString;
 var
   Word: UnicodeString;  // next word in input Str
@@ -823,7 +823,7 @@ function StrWrap(const Str: UnicodeString; const MaxLen, Margin: Integer):
   end;
 end;
 
-function StrWrap(const Paras: TStrings; const MaxLineLen, Margin: Integer;
+function StrWrap(const Paras: TStrings; const MaxLineLen, Margin: UInt16;
   const SeparateParas: Boolean): UnicodeString; overload;
 var
   Para: string;