Move some more files into subdirectories.

While I'm in the mood for cleaning up the top-level directory here:
all the 'nostuff.c' files have moved into a new 'stubs' directory, and
I broke up be_misc.c into smaller modules that can live in 'utils'.

stubs/nocmdline.c

@@ -0,0 +1,37 @@
+/*
+ * nocmdline.c - stubs in applications which don't do the
+ * standard(ish) PuTTY tools' command-line parsing
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include "putty.h"
+
+/*
+ * Stub version of the function in cmdline.c which provides the
+ * password to SSH authentication by remembering it having been passed
+ * as a command-line option. If we're not doing normal command-line
+ * handling, then there is no such option, so that function always
+ * returns failure.
+ */
+int cmdline_get_passwd_input(prompts_t *p)
+{
+    return -1;
+}
+
+/*
+ * The main cmdline_process_param function is normally called from
+ * applications' main(). An application linking against this stub
+ * module shouldn't have a main() that calls it in the first place :-)
+ * but it is just occasionally called by other supporting functions,
+ * such as one in uxputty.c which sometimes handles a non-option
+ * argument by making up equivalent options and passing them back to
+ * this function. So we have to provide a link-time stub of this
+ * function, but it had better not end up being called at run time.
+ */
+int cmdline_process_param(const char *p, char *value,
+                          int need_save, Conf *conf)
+{
+    unreachable("cmdline_process_param should never be called");
+}

stubs/nogss.c

@@ -0,0 +1,11 @@
+/*
+ * Stub definitions of the GSSAPI library list, for Unix pterm and
+ * any other application that needs the symbols defined but has no
+ * use for them.
+ */
+
+#include "putty.h"
+
+const int ngsslibs = 0;
+const char *const gsslibnames[1] = { "dummy" };
+const struct keyvalwhere gsslibkeywords[1] = { { "dummy", 0, -1, -1 } };

stubs/noprint.c

@@ -0,0 +1,38 @@
+/*
+ * Stub implementation of the printing interface for PuTTY, for the
+ * benefit of non-printing terminal applications.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include "putty.h"
+
+struct printer_job_tag {
+    int dummy;
+};
+
+printer_job *printer_start_job(char *printer)
+{
+    return NULL;
+}
+
+void printer_job_data(printer_job *pj, const void *data, size_t len)
+{
+}
+
+void printer_finish_job(printer_job *pj)
+{
+}
+
+printer_enum *printer_start_enum(int *nprinters_ptr)
+{
+    *nprinters_ptr = 0;
+    return NULL;
+}
+char *printer_get_name(printer_enum *pe, int i)
+{
+    return NULL;
+}
+void printer_finish_enum(printer_enum *pe)
+{
+}

stubs/norand.c

@@ -0,0 +1,22 @@
+/*
+ * Stub implementations of RNG functions for applications without an RNG. 
+ */
+
+#include "putty.h"
+
+void random_read(void *out, size_t size)
+{
+    unreachable("Random numbers are not available in this application");
+}
+
+void random_save_seed(void)
+{
+}
+
+void random_destroy_seed(void)
+{
+}
+
+void noise_ultralight(NoiseSourceId id, unsigned long data)
+{
+}

stubs/noterm.c

@@ -0,0 +1,16 @@
+/*
+ * Stubs of functions in terminal.c, for use in programs that don't
+ * have a terminal.
+ */
+
+#include "putty.h"
+#include "terminal.h"
+
+void term_nopaste(Terminal *term)
+{
+}
+
+int term_get_userpass_input(Terminal *term, prompts_t *p)
+{
+    return 0;
+}

stubs/notiming.c

@@ -0,0 +1,21 @@
+/*
+ * notiming.c: stub version of timing API.
+ *
+ * Used in any tool which needs a subsystem linked against the
+ * timing API but doesn't want to actually provide timing. For
+ * example, key generation tools need the random number generator,
+ * but they don't want the hassle of calling noise_regular() at
+ * regular intervals - and they don't _need_ it either, since they
+ * have their own rigorous and different means of noise collection.
+ */
+
+#include "putty.h"
+
+unsigned long schedule_timer(int ticks, timer_fn_t fn, void *ctx)
+{
+    return 0;
+}
+
+void expire_timer_context(void *ctx)
+{
+}

stubs/nullplug.c

@@ -0,0 +1,40 @@
+/*
+ * nullplug.c: provide a null implementation of the Plug vtable which
+ * ignores all calls. Occasionally useful in cases where we want to
+ * make a network connection just to see if it works, but not do
+ * anything with it afterwards except close it again.
+ */
+
+#include "putty.h"
+
+void nullplug_log(Plug *plug, PlugLogType type, SockAddr *addr,
+                  int port, const char *err_msg, int err_code)
+{
+}
+
+void nullplug_closing(Plug *plug, PlugCloseType type, const char *error_msg)
+{
+}
+
+void nullplug_receive(Plug *plug, int urgent, const char *data, size_t len)
+{
+}
+
+void nullplug_sent(Plug *plug, size_t bufsize)
+{
+}
+
+static const PlugVtable nullplug_plugvt = {
+    .log = nullplug_log,
+    .closing = nullplug_closing,
+    .receive = nullplug_receive,
+    .sent = nullplug_sent,
+};
+
+static Plug nullplug_plug = { &nullplug_plugvt };
+
+/*
+ * There's a singleton instance of nullplug, because it's not
+ * interesting enough to worry about making more than one of them.
+ */
+Plug *const nullplug = &nullplug_plug;