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.
Make sure dyld placeholders are prefixes

Mac OS X dyld placeholders should be always prefixes, otherwise this can lead
to some undefined behavior.
Resolve & replace @rpath placeholders

This is done by gathering LC_RPATH commands for main bundle executable and
using it for @rpath lookup in dependent frameworks.

All functions that need to carry rpaths to now take optional <rpaths> argument.

This enabled apps using @rpath to be bundled correctly, which will be necessary
for upcoming Qt 5.4 that will use @rpath for all frameworks.
Framework codesign Resources/Info.plist & Current

We need to ensure copied framework has proper layout with Resources/Info.plist
present next to versioned binary and Current symlink in Versions:

https://developer.apple.com/library/mac/technotes/tn2206

https://developer.apple.com/library/mac/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/FrameworkAnatomy.html

If Resources/ is not present we may try to copy Contents/Info.plist if present
to embedded Resources/Info.plist. This is a case of Qt5 that has
obsolete/invalid framework layout (see QTBUG-38511).
Make sure we bundle Qt5 Cocoa platform plugin

Otherwise CMake.app bundle will not run when using Qt5.
Merge topic 'fix-OSX-bundle-rpaths-and-Qt5' into next

9119ab6e Make sure we bundle Qt5 Cocoa platform plugin
55707fd5 Framework codesign Resources/Info.plist & Current
c4640a1e Resolve & replace @rpath placeholders
f8e4d2cb Make sure dyld placeholders are prefixes
26f7427f Use find on UNIX for fast executable lookup