build: fix up jsdoc return values

closes #2243
docs: add expressjs.kr(expressjs.com in Korean)

closes #2242
closes #2244
build: add Young Jae Sim as contributor
deps: debug@1.0.4
deps: finalhandler@0.1.0
Deprecate combined status, response signatures

closes #2227
deps: debug@1.0.4
deps: connect@2.24.0
deps: depd@0.4.2
deps: parseurl@~1.2.0
deps: send@0.7.0
Pass options from res.sendfile to send

fixes #2017
docs: replace Gittip badge
Fix req.protocol for proxy-direct connections

fixes #2252
3.15.0
deps: depd@0.4.2
deps: parseurl@~1.2.0
deps: update example dependencies
deps: jade@~1.5.0
deps: send@0.7.0