Many updates/fixes to 2018/burton2

This is a big commit but it should complete this entry and 2018 unless I
have missed something.

The make test rule was fixed. A script was not +x.

Renamed freqcount -> freqcount.sh (for browser/display).

Renamed mkkeywords -> mkkeywords.sh (for browser/display).

Renamed runtest -> runtest.sh (for browser/display).

Renamed spotcheck -> spotcheck.sh (for browser/display).

Renamed spotdiff -> spotdiff.sh (for browser/display).

Made tac.man proper man format and renamed tac.1.

Added tokcount.sh - a script that the author included in the remarks but
not in a script.

The renaming of files should be okay including the manifest (it is
believed this is true anyway).

Add try.sh script.

The READ_ME.txt was deleted as it had been renamed to author-README.txt
but the former was never deleted. This file was typo/format checked.

Format/typo check README.md file.

2018/burton2/runtest.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+: ${prog:=./prog}
+: ${opt:=crs}
+
+exec 2>&1
+for name in test*c fixed_iocccsize.c ioc_without_quote; do
+	/bin/echo -n "$name: "; $prog -$opt < $name
+done