Add the ability to select the file format (CSV or XLSX) in the export form.

Add "Select All" and "Select None" links to the export form to select all or no column checkboxes when using jquery.
Merge branch 'fileformat_select'
Merge pull request #7 from courtland/fileformat_select

Add the ability to select the file format (CSV or XLSX) in the export form
Merge remote-tracking branch 'upstream/master'
Fix invalid SQL exception when using field_search to filter against a relation column that is not in desired set of export columns.