Updated SamplingFeatures table and schema.

- Removed Sites.SiteID, made SamplingFeatureID the pk
- Removed Specimens.SpecimenID, made SamplingFeatureID the pk
  - But when removing Specimens.SpecimenID, got error message: Cannot be removed while used in fk fk_CalibrationStandards_Specimen. So:
    > Changed fk_CalibrationStandards_Specimen in ODM2Equipment.CalibrationStandards to use Specimens.SamplingFeatureID instead; but retained field name ODM2Equipment.CalibrationStandards.SpecimenID, for clarity
    > Deleted Specimens.SpecimenID
    > Set Specimens.SamplingFeatureID as the pk (also maintaining is as an fk)
- On ODM2Core.SamplingFeatures:
  - Added Notes field, as varchar(500)
  - Changed FeatureGeometry to Geometry type, and edited comment
  - Added SamplingFeatureName field (based on Emilio's use case)
  - Added SamplingFeatureGeotype field as varchar(50) (based on Emilio's use case)
Changed Identifier URN to URI, again.

I missed this in 2 of five tables.
Pull Master branch updates into EM's SamplingFeatures branch

Performed using text Find Differences tool in TextWrangler code editor.
 Let’s see if this now allows us to auto merge the branches!
merging
Merge pull request #14 from UCHIC/SamplingFeatures_em

Merging Sampling features em into master branch
Resolving conflicts in Taxonomic Classifiers feature branch