Start to tweak hush_supply and save old script to compare results

contrib/hush_supply

@@ -1,5 +1,5 @@
 #!/usr/bin/env perl
-# Copyright 2019 The Hush developers
+# Copyright 2019-2020 The Hush developers
 # Released under the GPLv3
 use warnings;
 use strict;

contrib/hush_supply_old

@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+# Copyright 2019-2020 The Hush developers
+# Released under the GPLv3
+use warnings;
+use strict;
+
+my $supply   = 0.0;
+my $block    = 0;
+my $satoshis = 100_000_000;
+my $amount   = int(12.5*$satoshis);
+my $halvings = 0;
+
+# Usage: ./hush_supply &> supply.csv
+
+# Use this to calculate when supply hits a certain value
+#while ($supply <= 21_000_000*$satoshis) {
+# Use this to calculate when block rewards end
+while ($halvings <= 64 && $amount >= 1) {
+    $block++;
+    if ($block < 5) {
+        $amount = 40_000 * $satoshis;
+    } else {
+        # Halving every 840000 blocks
+        if ($block % 840_000 == 0) {
+            $amount /= 2;
+            $halvings++;
+        }
+        $amount = int(12.5*$satoshis) / (2**$halvings);
+    }
+    $supply += $amount;
+    # block, current supply, block reward amount, number of halvings
+    printf "%s,%s,%s,%s\n", $block,$supply / $satoshis, $amount / $satoshis, $halvings;
+}