* Replaces AppendVPrintf with fmt::sprintf
* fmt::ArgList now used as a type safe alternative to varargs.
* Removed SIZE_T_FMT compatibility macros. fmt::sprintf is fully portable and supports %zu.
* Adds FLOG functions to log with fmt's native formatting style.
Stop using gdb on osx - was breaking the build
Add clang 3.5 build as travis now defaults to 5.0
Fix unknown-warning-option errors on AppleClang
ProtoProxy: Use nullptr
UrlClientTest: add override to callback destructor
Update jsoncpp to use nullptr
* Fixed Clang 5.0 compile errors
* Fixed wrong comment
* Only disable warnings in Clang 5 or higher
* Added a CMake condition for the Clang 5 no-zero-as-null-pointer-constant warning
* Now using the use_nullptr branch of the Cuberite specific SQLiteCpp fork
Two problems identified, both traced to commit 4315a11
(main.cpp) ParseArguments() was no longer being called before checking cRoot::m_RunAsService.
This led to m_RunAsService never being set (we use -d on the command line to instigate a service start).
(Root.cpp) Terminate events were being ignored when running as a service.
We only need to ignore the cin.good() call, not terminate events as a whole.
Ignore invalid or malformed command line parameters, prevent unhandled exceptions.
NOTE: Users will need to reinstall the service, now uses "-d" instead of "/service" in the start parameters.
Added "/service" switch, to prompt the binary to attempt starting as a service.
Added service* methods, to control service startup.
Split up main() into universalMain(), which contains the startup code for both service and normal start.
Added cRoot::m_RunningAsService bool,
Added cRoot::SetStopping(bool) to allow a stop request to be sent by the service controller.
Added cBlockIDMap::init() to avoid loading items.ini before the working directory has been set.
