More appropriate LegalCopyright field.

It doesn't make a lot of sense to have a Copyright notice on a Public
Domain work.  The intention of including the LegalCopyright version
string was solely to assert authorship.  The new string should make that
clearer.

version.cmd

@@ -44,7 +44,7 @@ if "%BUILD_ID%" == "" (set year=) else (
 @echo>>version.h.new #define NSSM_VERSIONINFO %major%,%minor%,%n%,%BUILD_NUMBER%
 @echo>>version.h.new #define NSSM_DATE _T("%DATE%")
 @echo>>version.h.new #define NSSM_FILEFLAGS %flags%
-@echo>>version.h.new #define NSSM_COPYRIGHT _T("(c) 2003-%year% Iain Patterson")
+@echo>>version.h.new #define NSSM_COPYRIGHT _T("Public Domain; Author Iain Patterson 2003-%year%")
 
 fc version.h version.h.new >NUL: 2>NUL:
 if %ERRORLEVEL% == 0 (del version.h.new) else (move /y version.h.new version.h)