[PATCH] Enhance platform support of hook script check-mime-type.pl (Windows)

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Enhance platform support of hook script check-mime-type.pl
Adopted from contrib/client-side/svn_load_dirs/svn_load_dirs.pl.in
(r1295006) [1]

* contrib/hook-scripts/check-mime-type.pl:
  (tmp_dir) Cross Platform: sane temp dir creation via File::Temp
function tempdir()
  (sub safe_read_from_pipe) Windows/DOS: does not support openfork and
files/paths with spaces have to be put in quotes

Patch by: Matthias Bücher <mail_at_maddes.net>

Tested with Subversion 1.6 to 1.8
for 1.8.5+ you also need Leo Davis' patch [4] (although I personally
kept chdir to temp dir)

[1]
http://svn.apache.org/viewvc/subversion/trunk/contrib/client-side/svn_load_dirs/svn_load_dirs.pl.in
[2] http://perldoc.perl.org/perlport.html#Interprocess-Communication-(IPC)
[3] http://perldoc.perl.org/perlport.html#PLATFORMS
[4]
http://mail-archives.apache.org/mod_mbox/subversion-dev/201403.mbox/%3C1576503.m6XB7udPXQ@hurry.speechfxinc.com%3E

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