Dropped in proof-of-concept search UI

Add sesarch_controller
Migrated view and actions from earlier version in mx
simple_matrix_browse branch
Not final UI, still needs cleanup
Trait groups are not used and neither is the higher order taxonomy
Add taxa scopes: species/family/order/genus/ungrouped
Link search into menu, move magnifying glass on search button
Fix bad link on categorical_traits -> categories
add 'active' class to selected navbar item
Add ungrouped taxa as htg