Merge pull request #44 from NESCent/fix_csv_download

Fix downloading of search results as CSV
Fix lambda for empty headers, provide empty arrays for defaults
Add template for SocialTraits
Make inputs for taxonomy small
Reduce size of selects for trait names
Tweaks to search results

Combine taxonomy in one column
Suppress truncation/popover if length<=30
Merge pull request #45 from NESCent/social_traits_template

Social traits template
Added comments about trait sets, mocked up a version in the YML
Add TraitSet model
Add trait_sets to import_template

First pass at implementation of nested trait sets
Began implementing trait_set_qualified_continuous_names

debugging recursion
Factored continuous and categorical out to common method
Refactoring in import_template.rb

Make trait_set_qualified_trait_names private
rename categorical_trait_names to categorical_trait_column_names, continuous_trait_names to continuous_trait_column_names
Added missing belongs_to :trait_sets
Support for delimited column names (to indicate trait set paths)
Initial implementation of TraitSets in import job

Not yet tested
Moved TraitSet creation by path to trait_set
Added relationships to project
Added migration for project relationships
Added ProjectsController and filters to select project