stack: print minimum stack size (1M) if current stack size is less than that
state: minor cleanups, optimizations and fixes

Log cleanup.
Indent cleanup (long lines).
State machine optimization: do not try to connect to itself.
Added 'connect' state for better logs and logic understanindg.
Comments fixes and cleanups.
Fixed leak when no sockets have been connected.
Print errno string and code when calling dnet_log_err().
Merge branch 'multibackend' of github.com:reverbrain/elliptics into multibackend
v2.26.3.2