ENH: BundleUtilities: Use find on UNIX for fast executable lookup

This commit integrates the upstream change kitware/cmake@6c31379

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Author: Adam Strzelecki <ono@java.pl> 2014-09-03 15:42:53
Committer: Brad King <brad.king@kitware.com> 2014-10-10 10:15:56

BundleUtilities: Use find on UNIX for fast executable lookup

It makes whole executable process quicker on UNIX, especially for large bundles
containing many files, since using find narrows results to only files having
executable flags then all further tests follow.

Since find ... -perm +0111 is not clearly POSIX compliant and some Linux
versions refuse it, it is better to use longer but portable:

   find ... -perm \( -perm -0100 -o -perm -0010 -o -perm -0001 \)

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git-svn-id: http://svn.slicer.org/Slicer4/trunk@23988 3bd1e089-480b-0410-8dfb-8563597acbee