backport config dsl from v11
missed to fix test
fix to return self after instance_eval
Merge pull request #177 from sabottenda/fix_eval_dslparser

fix to return self after instance_eval
Goodbye incomprehensible code indent! Yay!!
Add format option to in_exec plugin
Improve in_exec test
Fix copy and paste invalid name of GCStat test
Use Fluent::ExecUtil parsers instead of own Parser in out_exec_filter
Remove 1.9.2 test because 1.9.2 is dead
Skip nil record at input and engine. fixes #176
v0.10.37