Move SetLogger and SetAborter from libbase to liblog

libbase is copied into each APEX module which requires it, meaning
that there may be multiple instances of libbase running within a
single process with their own copy of libbase's globals.  This means
that SetLogger() and SetAborter() will only impact logs from the
instance of libbase that calls it.  This change moves this state to
liblog, since it will only ever have one instance in a single
process.

One major side-effect here is that now both ALOGE style and LOG(...)
style logs will be handled through the same logger function.  For
example, a logger specified through libbase's SetLogger() will now see
logs sent to liblog through ALOGE().  This is intended behavior.

A second side-effect is that libbase's stderr logger is used for all
host logging now.  It's simply a better logging default than the
fake_log_device logger in liblog currently and makes ALOGE and
LOG(...) logs on host follow the same format.

Bug: 119867234
Test: libbase and liblog unit tests; logging works
Change-Id: Ib52cbfb4e43749e50910ed19a993dffae19ace86