Try building on OS X with libc++

(cherry picked from commit 327181ef18fee22e2c05f2e8303efeffdc63cae0)
Change some API URLs to use https.
Print out the Clementine display version in the cmake summary.
Use std::unique_ptr instead of boost:scoped_ptr in one place.
Add trailing underscore to class member variable.
Merge pull request #4155 from paperbagcorner/underscore

Add trailing underscore to class member variable.
Do not log IP address from network remote settings.
Reformat all Objective-C++ files with clang-format.

clang-format -style=Google -i src/*/*.mm
[Desktop file] Serbian translations
[Desktop file] Add Audio group
Merge pull request #4156 from pejakm/srtrans

[Desktop file] Serbian translations
Merge pull request #4157 from pejakm/desktopfile

[Desktop file] Add Audio category
Merge pull request #4145 from sobkas/master

Initial support for "Copy to device" in a podcast section