In the right-hand pane, two folders that were at the same path and whose
names started with the same characters were considered to be nested by
the breadcrumbs trail.

E.g, folders named "abc" and "abcd", both in the "Audio" folder:
clicking on "abcd" made the breadcrumb trail display "[Audio] > [abc] >
[abcd]"

- The background selection palette now includes a slider to change the
size of the background grid. Default min/max values are 16 and 64px,
defined in UBSettings. Grid resizes dynamically as the slider is moved.
- Measuring tools' (ruler, triangle) markers follow grid size: 1 square
of the background grid corresponds to 1cm
- Grid size can be different for each page of a document
- Grid size is saved in the .svg
- Documents with a background grid but no specified grid size follow the
default size defined in UBSettings.

Previously, grid size was calculated based on DPI, which can vary from
one OS, computer or display to the next. This new setting allows
documents to be migrated from one machine to another with no unexpected
changes in grid size happening. It also makes it easy to correct any
problems importing old documents (whose grid size might be smaller or
larger than expected when imported on a new version of OpenBoard).

Caused problems e.g with podcast mode, where if the control and display
views were swapped in the preferences, the wrong screen would be recorded
when switching to desktop mode during recording of the podcast.
This happened even if only one screen was plugged in, so a black screen
was recorded in that case (at least on OS X 10.10)

Also quick code clean-up in UBDocumentController

Mostly, removal of old code that had been commented out instead of
removed

The project didn't compile on Windows.. list of modifications:

- Added essential changes that hadn't been committed / pushed (Qt4->Qt5
changes; other misc. changes by Abdel)
- Temporarily disabled podcasts, as the modules don't compile with Qt5.2/
5.5

Currently, the application compiles on Windows, with MSVC2010 32-bit

Application compiles and runs, with some caveats. Full list of changes:

- minor changes related to Qt4->Qt5 API differences

- Replaced calls to Carbon framework by Cocoa

- Removed registering of AE event handler. Seems to be done
automatically in Qt5.

- temporarily removed Podcast functionality, pending (presumably)
complete re-write due to Quicktime being obsolete in newer OS X
versions.

- Created OBCocoa namespace, and associated files src/core/OBCocoa.h/.mm, to
handle OS X - specific system calls. Currently used only by
UBApplication, but can in the future provide a useful interface between
the cocoa framework and OB, to avoid having too much OSX-specific code
in various files

Q_WS_MACX -> Q_OS_OSX
Q_WS_MAC -> Q_OS_OSX
Q_WS_WIN -> Q_OS_WIN
Q_WS_X11 -> Q_OS_LINUX

Added loadAcquire() to get int value of QAtomicInt variables. (Was previously done automatically with the operatorint() of QAtomicInt)

added 'supportedDragActions' function to replace functionality provided by 'setSupportedDragActions' function (obsolete)

The empty name should be avoided and the same directory name too. File name could have the same name this is as before