Move src/*.{c,h} to src/core/

This way we have all libosmocore.so in an own subdir instead of having
lots of files in the parent dir, which also contains subdirs to other
libraries.
This also matches the schema under include/osmocom/.

Change-Id: I6c76fafebdd5e961aed88bbecd2c16bc69d580e2
---
M Doxyfile.core.in
M Makefile.am
M configure.ac
M debian/copyright
M src/Makefile.am
M src/codec/Makefile.am
M src/coding/Makefile.am
A src/core/Makefile.am
R src/core/application.c
R src/core/backtrace.c
R src/core/base64.c
R src/core/bitcomp.c
R src/core/bits.c
R src/core/bitvec.c
R src/core/context.c
R src/core/conv.c
R src/core/conv_acc.c
R src/core/conv_acc_generic.c
R src/core/conv_acc_neon.c
R src/core/conv_acc_neon_impl.h
R src/core/conv_acc_sse.c
R src/core/conv_acc_sse_avx.c
R src/core/conv_acc_sse_impl.h
R src/core/counter.c
R src/core/crc16.c
R src/core/crcXXgen.c.tpl
R src/core/exec.c
R src/core/fsm.c
R src/core/gsmtap_util.c
R src/core/isdnhdlc.c
R src/core/it_q.c
R src/core/logging.c
R src/core/logging_gsmtap.c
R src/core/logging_syslog.c
R src/core/logging_systemd.c
R src/core/loggingrb.c
R src/core/macaddr.c
R src/core/mnl.c
R src/core/msgb.c
R src/core/msgfile.c
R src/core/panic.c
R src/core/plugin.c
R src/core/prbs.c
R src/core/prim.c
R src/core/probes.d
R src/core/rate_ctr.c
R src/core/rbtree.c
R src/core/select.c
R src/core/sercomm.c
R src/core/serial.c
R src/core/signal.c
R src/core/sockaddr_str.c
R src/core/socket.c
R src/core/stat_item.c
R src/core/stat_item_internal.h
R src/core/stats.c
R src/core/stats_statsd.c
R src/core/stats_tcp.c
R src/core/strrb.c
R src/core/tdef.c
R src/core/thread.c
R src/core/time_cc.c
R src/core/timer.c
R src/core/timer_clockgettime.c
R src/core/timer_gettimeofday.c
R src/core/use_count.c
R src/core/utils.c
R src/core/write_queue.c
M src/ctrl/Makefile.am
M src/gb/Makefile.am
M src/gsm/Makefile.am
M src/sim/Makefile.am
M src/usb/Makefile.am
M src/vty/Makefile.am
M tests/Makefile.am
M utils/Makefile.am
M utils/osmo-stat-dummy/Makefile.am
77 files changed, 146 insertions(+), 140 deletions(-)