Dropping non-strftime() support and fixing -Werror problem
Problem:
a) when running ./configure, strftime() and other functions cannot be
properly detected, since autoconf generates crappy test code, which
at least fails when warnings are treated as errors (gcc: -Werror).
b) strtime() is standard since C89, so we can simply expect it to exists
(if there's *really* some acient box out there breaking mc build,
it's libc/toolchain should be fixed ;-p)
Solution:
Remove the checks for strftime() and all workarounds