don't rescan unchanged files if library has been unavailable
Use c++11 instead of boost where possible.
Use nullptr instead of NULL everywhere.
Hide use of boost multi-index behind pimpl.
Build spotify blob as c++11
Remove boost from tests.
Add missing header for syscall().

This is cunningly not defined in syscall.h
removed useless debug log
Add missing include for symlink()
Merge pull request #4182 from sobkas/master

Fix auto download podcasts
Merge pull request #4161 from BrummbQ/master

don't rescan unchanged files if library has been unavailable.  Fixes #3032
Do not translate ip address.
Merge pull request #4187 from paperbagcorner/ip-notrans

Do not translate ip address.
Add missing header for _exit()

Fixes #4188
Reformat all non-3rd-party C/C++/Objective-C++.

Command line:
find src ext -regex '.*\.\(h\|cpp\|mm\)' -exec clang-format -i
 -style='{BasedOnStyle: Google, DerivePointerBinding: false}' {} \;