fix install target

Source/cmInstallFilesCommand.cxx

@@ -63,7 +63,7 @@ void cmInstallFilesCommand::FinalPass()
       {
       // replace any variables
       std::string temps = *s;
-      testf = temps + ext;
+      testf = cmSystemTools::GetFilenameWithoutExtension(temps) + ext;
       // add to the result
       targetSourceLists.push_back(testf);
       }

Source/cmInstallFilesCommand.h

@@ -70,9 +70,9 @@ public:
   virtual const char* GetFullDocumentation()
     {
     return
-      "INSTALL_FILES(path extension srclist file file srclist ...)\n"
+      "INSTALL_FILES(path extension file file ...)\n"
       "INSTALL_FILES(path regexp)\n"
-      "Create rules to install the listed files into the path. Path is relative to the variable CMAKE_INSTALL_PREFIX. There are two forms for this command. In the first the files can be specified explicitly or by referenceing source lists. All files must either have the extension specified or exist with the extension appended. A typical extension is .h etc... In the second form any files in the current directory that match the regular expression will be installed.";
+      "Create rules to install the listed files into the path. Path is relative to the variable CMAKE_INSTALL_PREFIX. There are two forms for this command. In the first the files can be specified explicitly. If a file specified already has an extension, that extension will be removed first. This is useful for providing lists of source files such as foo.cxx when you want the corresponding foo.h to be installed. A typical extension is .h etc... In the second form any files in the current directory that match the regular expression will be installed.";
     }
   
   cmTypeMacro(cmInstallFilesCommand, cmCommand);