pterm.exe: run command-line options through cmdline.c.

This makes pterm.exe support the same (very small) subset of the
standard option collection that Unix pterm does. Namely, -load (which
won't do anything useful with a hostname to connect to, but is still
useful if you have a saved session containing configuration like
colours or default size or what have you), and also -sessionlog.

To make this work, I've had to move the 'tooltype' definition out of
window.c into {putty,pterm}.c, so that it can be defined differently
in the two.

windows/putty.c

@@ -6,6 +6,11 @@ extern const char *dialog_box_demo_screenshot_filename;
 static strbuf *demo_terminal_data = NULL;
 static const char *terminal_demo_screenshot_filename;
 
+const unsigned cmdline_tooltype =
+    TOOLTYPE_HOST_ARG |
+    TOOLTYPE_PORT_ARG |
+    TOOLTYPE_NO_VERBOSE_OPTION;
+
 void gui_term_process_cmdline(Conf *conf, char *cmdline)
 {
     char *p;