Adjusted search help hints
Fixed a NPE

Fix for:
https://github.com/openmicroscopy/openmicroscopy/pull/2676#issuecomment-48910713
Workaround for file annotations not being part of annotation index
Caught "TooManyClauses" error
Splitted acquisition and import date column
Corrected some weird whitespace code formatting issues
Fixed a travis compile error
Fixed issue with View button on search results table
Disabled table column dragging
Show "No results found" if there are no results
Decreased row height for search result table
Made import date the default
Allow date range only searches
Updated search help text and URL
Added tooltip to date combobox
Just copied the 'search hints' from Web
Changed date format of the search results
Merge pull request #2806 from dominikl/search_improvements_3

Latest changes/fixes for Insight search