Export includes to $CORE_INCS

1.1.0

includes export to CORE_INCS

Support compilation with version lesser than 1.11.5

Merge pull request #2 from eugenepaniot/master

Fix compilation on nginx 1.10.

Fixes

1. fix last checked time in nginx upstream module when up/down peer.

1.0.0

v.1.0.0