Fixes linux.sh hints file for Ubuntu multi-arch

This updates to the latest linux.sh hints file, which is necessary
to build older Perls on recent Ubuntu machines.
Bump version 0.46
Add HPUX hints file

  commit 9cfd094e6d0a842551c1c58e998eb057cd8425e3
  Author: H.Merijn Brand <h.m.brand@xs4all.nl>
  Date:   Thu Aug 4 09:20:32 2011 +0200

    Support gcc-4.x on HP-UX PA-RISC/64

    Correct the socketsize. Probably due to big-endian versus
    little-endian, this has always worked on Intel CPUs. This
    is a very very old problem,  and it has been the reason I
    never used gcc-4 on PA-RISC,  because perl would not pass
    the test suite in 64bitall.

    Noticeable effects of wrong "$socksizetype" are return codes
    of 0 (pass) from functions like getpeername (),  but invalid
    (or none) data in the returned structures or a return length
    of 0 or 256. In the latter case, the length is stored in the
    second part of the 64bit long and the 32bit first part is 0.
    This might be true on Intel-like machines too, but the tests
    will pass, as the significant part of the returned length is
    in the first 32bits and a pointer to int will still see that
    correct.  Mind that in that case the 32bits after that might
    have been overridden => can of worms.
Specify Perl version for perlbrew & perl5.005
Bump to version 0.50
Correctly determine Perl source version even old stuff.
Bumpity version to 0.52
Add patching of make_ext.pl for virtualisation fixes
Fix previous update
Fix v5.14-ism in regex. Reported by Gregor Herrmann [rt.cpan.org #71416]
Autoguessing perl versions was broken, it is fixed now.

Thanks to Tom Molesworth and Paul Evans for helping to spot this.
Update FreeBSD hints to support FreeBSD 10.0
Added a plugin system
Added cygwin hints file
Updated hints files, includes support for NetBSD 6.*
Updated Linux hints which includes gcc search libraries localisation fix
Clarify in the POD, we only facilitate building not testing
Add v5.8.9 patch

[perl #63886] 5.8.9 binary incompatibility with PL_perlio_mutex

Applied as:

commit 03fe696d61d94bd59d878a9f81b0af85465d7e1e
Author: From: Edward Moy <emoy@apple.com>
Date:   Sun Jul 8 23:01:23 2012 -0700
[rt.cpan.org #79223] bad patch for 5.8.9 in 0.74

Patch for perlio.c is for patch -p1 while module runs -p0.

Signed-off-by: Chris 'BinGOs' Williams <chris@bingosnet.co.uk>
Added midnightbsd hints file which supports 0.4