Add log_level option to each plugin
Replace  with log/@log to support log_level option
require sigdump
Merge pull request #256 from sonots/sigdump

Add sigdump
Merge pull request #255 from fluent/add-log-level-option

Add log_level option
Use  instead of log in in_tail configure for better warning
Remove dump_stacktrace from delegators because it has own log level
v0.10.43