Improve printed output

Get rid of inconsistencies in the printed output (error printing,
colors, etc.).

Prepare for user configurable color.

Cleanup.

src/print.c

@@ -0,0 +1,53 @@
+/*
+ * tio - a simple TTY terminal I/O application
+ *
+ * Copyright (c) 2014-2022  Martin Lund
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include "print.h"
+
+bool print_tainted = false;
+bool print_color_mode = false;
+const char *print_color = ANSI_COLOR_YELLOW;
+
+void print_hex(char c)
+{
+  if ((c == '\n') || (c == '\r'))
+  {
+    printf("%c", c);
+  }
+  else
+  {
+    printf("%02x ", (unsigned char) c);
+  }
+
+  fflush(stdout);
+}
+
+void print_normal(char c)
+{
+  putchar(c);
+  fflush(stdout);
+}
+
+void print_set_color_mode(bool mode)
+{
+  print_color_mode = mode;
+}