Variable name changes in Monty pre-JSON objects

[hamishwp]

The following should be changed and then added to the AddEmptyColImp function:

• All variable names to lowercase
• Add longitude+latitude to EM-DAT, Desinventar, IDMC, etc
• Add IDMC IDU API data
• Modify GO src_db_lab values
• "GLIDE" - "ext_ID"
• Add longitude and latitude points of event as spatial point in impact spatial
• change "_fileread" to "_format", check "_spat_fileloc" and "_spat_URL"
• Check "resunits" in Monty taxonomies
• src_addinfo to be sorted