core/ns: fix resource leak

Reported by Coverity as CID #1142191
yaml: fix memory leak

Reported by Coverity as CID #971051.
core/hooks: fix typo

which leds to coverity issues :)

Reported by Coverity as CID #1142190 and #1142186
plugins/corerouter: check return value of bind_to_unix_dgram

Reported by Coverity as CID #1142187
plugins/python: fix uwsgi_python_harakiri error handling

Fixes close with a negative fd.

Reported by Coverity as CID #970996.
Merge pull request #491 from xrmx/coverity2312-3

Coverity2312 3