Partial fix of #128, /core/issue -> /issue
Merge pull request #285 from hyperkang/iss128_core_issue

Remove /core prefix #128
bugfix (dev environment)
only allow one URL per issue (SEO optimization)
only allow one URL per issue (SEO optimization)
path fixes
... to make google happy
trying to improve performance for /sitemap.xml
still trying
test fix
trying to improve coverage report
improving coverage report