additional fixes and changes

change sort to be the following: order by modified date by default in
ascending order, when sorting by title & author sort by descending order
first
Fix Data Investigation menu typo
Remove taxonomy link from keyword rendering
modify text area field instance definition with wysiwyg setting
modify edit form of existing data investigation to set text format field
due to change in wysiwyg setting
Merge pull request #40 from ooiepe/develop-release-3.4-additional-bug-fix

Additional fixes and changes for 3.4