Add missing WT_ATOMIC functions and log config.
Start logging implementation
Merge branch 'develop' into logging.  Commit merge conflicts.

Conflicts:
	dist/stat_data.py
	src/conn/conn_api.c
	src/conn/conn_open.c
	src/include/wiredtiger.in
Commit log.h and comments in log.c
First pass that compiles.
Working slot code.
Add code when lock is available back in.
Add switching of log files.
Initialize tmp slot structure.
Add file_max config back in.  Fix a few statistics.
Add direct_io support for logging.
Use __wt_chksum not hash.
Add sync support, return LSN and print thread id.
Add missing log related files.
Group error support.
Some clean-up.
Ifdef out use of slot_cond.
Merge branch 'develop' into logging

Conflicts:
	src/config/config_def.c
	src/os_posix/os_open.c
Merge branch 'develop' into logging
Merge develop into logging.