Install in sub-directory support.

refs #527
Merge pull request #1523 from halfdan/527-subdir-support
Fix failing casper tests

no issue
- spam test: changed waitForSelector to waitForText
- feature test: changed waitForRessource to watiForSelector
Merge pull request #1559 from sebgie/failing-tests

Fix failing casper tests
first pass at prevpost and nextpost

closes #529

makes previous and nextpost available when a post has been selected