add geometry column to sites RM-1694

- Add geometry column to sites, initialized with data (lat, lon, masl)
[masl == elevation]
- All sites are set to have srid/espg=4326 (WGS-84)
- Need to switch database.yml to use postgis instead of postgresql
improvements to spatial code

- add index to geometry
- use centroid if not a point
- remove activerecord-postgresql-adapte, is replaced by
activerecord-postgis-adapter
update
add comment about 4326
Merge branch 'master' into RM-1694-geometry-column
Merge branch 'master' into RM-1694-geometry-column
Updated Gemfile.lock and updated sites fixture to work with updated
table definition.
Merge branch 'RM-1694-geometry-column'
Make tests use capybara-webkit by default.  Made new environment
test_no_js for users who don't want to use the webkit.  So "test"
replaces "test_js" and "test_no_js" replaces "test".
Eliminated test_no_js environment support.
replaced corrupted willow_yield_grid.csv file; it is redundant (public/temp_models was replaced by local/modelout), but this should avoid confusion
Merge branch 'master' of github.com:PecanProject/bety
replaced incorrect legend for willow yield map
Merge branch 'feedback_update' of git://github.com/phenolphtalein/bety into phenolphtalein-feedback_update
Added comment with "TODO" note to fbtab partial.
Merge branch 'phenolphtalein-feedback_update'
(Prevent unstyled page from flashing into view.)
In "unlink_covariate", don't try to delete a covariate from the
trait's covariate list before destroying it: the SQL UPDATE statement
triggered by a delete will be prevented by the
"restrict_covariate_range" trigger function if the level attribute of
the covariate is out of range and will trigger an exception.
Updated production structure file.
cropped willow map legend
Restyle the new and edit trait pages.