Add new calls sd_bus_open() and sd_bus_default() for connecting to the
starter bus a service was invoked for, or -- if the process is not a
bus-activated service -- the appropriate bus for the scope the process
has been started in.
A compatibility libsystemd-login library is created which uses
.symver and ifunc magic proposed by Lennart to make programs linked
to the old library name continue to work seamlessly.
Unfortunately the bfd linker crashes:
https://sourceware.org/bugzilla/show_bug.cgi?id=16467
This will be fixed in binutils 2.25.
As a work-around, gold can be used:
LDFLAGS=-Wl,-fuse-ld=gold
Unfortunately the switch to pick the linker appeared in gcc 4.8.
This also doesn't work with LLVM:
http://llvm.org/bugs/show_bug.cgi?id=11897
This brings the calls into similar style as the respective functions in
libsystemd-journal, and also is a bi shorter and more descriptive since
it clarifies the time unit used.