Incorporate some git information into NetHack

Incorporate some git information into NetHack so that it
is potentially visible to a player. That's useful when
collecting details about the version that they are
running and, if the gitinfo is present, it can tie the
code to a specific git commit in the repository.

This modifies 'makedefs -v' to check for the presence of a data file
called dat/gitinfo.txt and if it is there, parse out its
contents, then write additional lines to include/date.h beyond
what 'makedefs -v' was previously putting in there, similar to
this sample:

      #define NETHACK_GIT_SHA "0c84e564c78e2024e562d39539376ce2e21eec8e"
      #define NETHACK_GIT_BRANCH "NetHack-3.6.0"

The contents of an appropriate dat/gitinfo.txt are as follows,
and trailing/leading whitespace is not significant:

      githash = 0c84e564c78e2024e562d39539376ce2e21eec8e
      gitbranch = NetHack-3.6.0

It also adjusts the contents of the 'v' version information to
include the additional git info when available.

Also adds some hooks DEVEL/hooksdir and a perl file to DEVEL
for simplifying and automating the deposit of dat/gitinfo.txt
so that it generally reflects the most current git commit.

DEVEL/gitinfo.pl can be used to build dat/gitinfo.txt at any
time without doing a commit, merge, or checkout.
    	perl DEVEL/gitinfo.pl

command line --version and -version support

To complement the extra information being provided in the
version by the 'v' command, this also adds support for the
following new command line arguments:
    --version
     -version            Output the NetHack version string then exit.

    --version:paste      Output the NetHack version string and also copy it to
     -version:paste      the platform's paste buffer for insertion somewhere,
                         then exit.

If the paste variation of -version is requested on a platform that
hasn't incorporated any support for the capability, it will deliver
the version info then an error message, prior to exiting.

To support the extended -version:paste variation, a port needs to:
    - provide a port-specific routine to perform
      the paste buffer copy in a port code file.
    - #define RUNTIME_PASTEBUF_SUPPORT in the include/portconf.h header file.

    --skeleton--
    void port_insert_pastebuf(buf)
    char *buf;
    {
    	/* insert code to copy the version info from buf into
    	   platform's paste buffer in a supported way */
    }

macosx and Windows have both added support for RUNTIME_PASTEBUF_SUPPORT

src/allmain.c

@@ -737,5 +737,87 @@ const char *msg;
     }
 }
 
+/*
+ * Argument processing helpers - for xxmain() to share
+ * and call.
+ *
+ * These should return TRUE if the argument matched,
+ * whether the processing of the argument was
+ * successful or not.
+ *
+ * Most of these do their thing, then after returning
+ * to xxmain(), the code exits without starting a game.
+ *
+ */
+
+static struct early_opt earlyopts[] = {
+    {ARG_DEBUG, "debug", 5, FALSE},
+    {ARG_VERSION, "version", 4, TRUE},
+};
+
+boolean
+argcheck(argc, argv, e_arg)
+int argc;
+char *argv[];
+enum earlyarg e_arg;
+{
+    int i, idx;
+    boolean match = FALSE;
+    char *userea = (char *)0, *dashdash = "";
+
+    for (idx = 0; idx < SIZE(earlyopts); idx++) {
+        if (earlyopts[idx].e == e_arg)
+            break;
+    }
+    if ((idx >= SIZE(earlyopts)) || (argc <= 1))
+            return FALSE;
+
+    for (i = 1; i < argc; ++i) {
+        if (argv[i][0] != '-')
+            continue;
+        if (argv[i][1] == '-') {
+            userea = &argv[i][2];
+            dashdash = "-";
+        } else {
+            userea = &argv[i][1];
+        }
+        match = match_optname(userea, earlyopts[idx].name,
+                    earlyopts[idx].minlength, earlyopts[idx].valallowed);
+        if (match) break;
+    }
+
+    if (match) {
+        switch(e_arg) {
+            case ARG_DEBUG:
+                        break;
+            case ARG_VERSION: {
+                        boolean insert_into_pastebuf = FALSE;
+                        const char *extended_opt = index(userea,':');
+
+                        if (!extended_opt)
+                            extended_opt = index(userea, '=');
+
+                        if (extended_opt) {
+                            extended_opt++;
+                            if (match_optname(extended_opt, "paste",
+                                                   5, FALSE)) {
+                                insert_into_pastebuf = TRUE;
+                            } else {
+                                raw_printf(
+                     "-%sversion can only be extended with -%sversion:paste.\n",
+                                            dashdash, dashdash);
+                                return TRUE;
+            		    }
+        		}
+                        early_version_info(insert_into_pastebuf);
+                        return TRUE;
+                        break;
+            }
+            default:
+                        break;
+        }
+    };
+    return FALSE;
+}
 
 /*allmain.c*/