Fix require’s get-magic handling for @INC elements

It was only calling get-magic before checking whether the argument was
a reference if the array was tied, which is not the only thing that
can cause an @INC element to have get-magic.  It should have been
checking for get-magic on the element itself (which is a faster
check, too).

And then there were too many FETCH calls.

I do not know whether we should be calling get-magic exactly once
when the ‘Can’t locate’ error occurs.  At least this commit reduces
the number of FETCHes.
perldiag: Use (F) consistently

and explain in the prose when there is an error.  One entry already
explained this.
perldiag: Rewrap an entry for better splain output
Update Module-Build to CPAN version 0.4204

  [DELTA]

0.4204 - Fri Jan 10 00:29:31 CET 2014

  [BUG FIXES]

  - Map conflicts back to runtime [Leon Timmermans]

  - Use mod2fname whenever it's available [Leon Timmermans, Brian Fraser]

  - Accept custom entries in meta_merge 1.4
Add Russel O'Connor to AUTHORS

Apparently he was the original author of commit b0d9ce3858 (Oct ’99).
t/re/pat.t: Keep minitest passing
pp_sys.c:S_doform: remove redundant null check

This static function is called from exactly two places that both die
aforehand if cv is null.  Further, the cv parameter is already marked
as non-null.
pp_ctl.c:pp_require: Remove redundant VMS null checks

SvPVX(newSVpv("",...)) should never return null.
Use NOT_REACHED in one more place in op.c

Under clang, this reduces the size of op.o by 16 bytes.

$ clang -v
Apple LLVM version 4.2 (clang-425.0.27) (based on LLVM 3.2svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
reduce size of const static tables in time64.c

The data in the const static arrays can be expressed with smaller
datatypes. This reduces binary size slightly.
correct a Pod warning in the new perldelta template

(cherry picked from commit 1332f10946560bb419517a581b7f56982fcc659f)
perldelta for c3970b8037
Make getc unset the utf8 flag on its retval

The same scalar (the target) is used to return the value each time the
same getc operator is called.  It was turning on the utf8 flag when
necessary, but not turning it off.

(I suspect recv has the same bug.  I haven’t confirmed.)
Configure: Better guesses for usrinc and friends on some compilers

It turns out that we had some much more accurate way of getting
usrinc, libpth and incpth -- we can just ask the compiler.  This
was stashed away and only used when cross-compiling; what this
commit does is move things around so that it's also used in the
more common case.
Configure: Add $cppflags to cppstdin
Configure: Change a use of cc to $cc
Configure: use incpth, not usrinc, to search for headers.

incpth is all the paths that will eventually be used by the compiler to
search for headers; usrinc is the first of those paths to have all three
of errno.h, stdio.h, and time.h inside.
Introduce sysroot variable to Configure

This is borrowed from gcc and allows us to indicate the logical root
directory for headers and libraries, under which all -I and -L are
searched for. This patch adjusts Configure to search under $sysroot
(if supplied) for headers and libraries, instead of /.

--sysroot is added to ccflags and friends so that make in
ExtUtils::MakeMaker, and other extensions, will use it.

Currently this is only done if compiling with some variant of gcc
or g++.
Configure, sysroot: add --sysroot to cppflags
Configure, sysroot: Update defaults to use $sysroot