Add ctype test

Manipulating the character class table in ctype.c by hand is error prone.
To ensure that typos are found quickly, add a test program and script.

test-ctype checks the output of the character class macros isspace() et.
al. by applying them on all possible char values and consulting a list of
all characters in the particular class.  It doesn't check tolower() and
toupper(); this could be added later.

The test script t0070-fundamental.sh is created because there is no good
place for the ctype test, yet -- except for t0000-basic.sh perhaps, but
it doesn't run well on Windows, yet.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0070-fundamental.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+test_description='check that the most basic functions work
+
+
+Verify wrappers and compatibility functions.
+'
+
+. ./test-lib.sh
+
+test_expect_success 'character classes (isspace, isalpha etc.)' '
+	test-ctype
+'
+
+test_done