Update Help Document and Minor bug fix (#275)

1. Update help document for new features.
2. Fixed "FamicomDiskSytem" typo in hnd file.
3. Fixed a bug of RAM Watch.

src/drivers/win/header_editor.cpp

@@ -1637,6 +1637,7 @@ bool SaveINESFile(HWND hwnd, char* path, iNES_HEADER* header)
 	{
 		sprintf(buf, "Creating target file %s failed.", path);
 		MessageBox(hwnd, buf, "iNES Header Editor", MB_OK | MB_ICONERROR);
+		FCEU_fclose(source);
 		return false;
 	}
 

src/drivers/win/ramwatch.cpp

@@ -980,6 +980,12 @@ INT_PTR CALLBACK EditWatchProc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lPara
 						// get the address(es)
 						char str_addrs[1024];
 						GetDlgItemText(hDlg, addrCtrlID, str_addrs, 1024);
+						if (!str_addrs[0])
+						{
+							MessageBox(hDlg, "You must enter an address.", "Error", MB_OK | MB_ICONERROR);
+							return true;
+						}
+						
 						char* next = strtok(str_addrs, ",");
 						int i = 0;
 						unsigned int addrSize = 4;