Add ctype test

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>