Add blackbox_less. (#263)

* Add blackbox_view and use PAGER (default to less)

bin/blackbox_view

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+#
+# blackbox_view -- Decrypt a file, view it, shred it
+#
+set -e
+source "${0%/*}/_blackbox_common.sh"
+
+for param in "$@" ; do
+  shreddable=0
+  unencrypted_file=$(get_unencrypted_filename "$param")
+  if [[ ! -e "$unencrypted_file" ]]; then
+    "${BLACKBOX_HOME}/blackbox_edit_start" "$param"
+    shreddable=1
+  fi
+  ${PAGER:-less} "$unencrypted_file"
+  if [[ $shreddable = 1 ]]; then
+    shred_file "$unencrypted_file"
+  fi
+done