Merge pull request #5 from PoPoutdoor/develop

Fix #3 Not import RSS feed without timestamp
Merge pull request #6 from PoPoutdoor/develop

Fix #4, add rdf support
Merge pull request #7 from PoPoutdoor/develop

Add GitHub link to user-agent header
Merge pull request #8 from PoPoutdoor/develop

Update title
Merge pull request #9 from PoPoutdoor/develop

fix typo
Truncate Title only for Topic mode
Update header sent to fix 400 response