OS X: rename special menu items instead of duplicating

Two-part fix: QCocoaMenu::syncMenuItem, when selecting the "old" menu,
if an item was merged, 'applicationMenu' was always selected, but this
is wrong for any item with a role >= CutRole (such an item still can
be "merged", but it's not in the application menu).

QCocoaMenuItem::sync - item can be merged with itself: after item's
role detected, the search for an item to merge with can find exactly
the same item we've just detected the role for (since a data-member is
modified) - try to avoid this.

Task-number: QTBUG-39934
Change-Id: Ibe1df9e92973380652101143067e14922afdfb9e
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Account for the country/language settings when checking for duplicates

When a file has the same alias but a different country or language setting
then it should not warn about it being a potential duplicate.

Task-number: QTBUG-19286
Change-Id: I60a9c422ff02214399bdea3791374a65c9f6c604
Reviewed-by: hjk <hjk121@nokiamail.com>
qiosclipboard: take ownership over mime data

QClipboard is documented to take ownership over
the mime data set with "setMimeData" and the value
returned by "mimeData". So we need to implement
this to avoid memory leaks.

Change-Id: Ieb3a17368ed3a698c29a7f92c8ee87a0cca86b46
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>
Remove duplicate of clang + libc++ mkspec

The same funcionality is already supported, so we avoid confusion.
The corresponding mkspec is name "linux-clang-libc++"

Change-Id: Ib087595298b48c73ad5da8d92cca2d1bac89f2be
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>