fix: inputs/bien2_traits/TraitObservation/map.csv: mapped VisitingDate to eventDate

moved everything into /trunk/ to create the standard svn layout, for use with tools that require this (eg. git-svn). IMPORTANT: do NOT do an `svn up`. instead, re-use your working copy's existing files with `svn switch` (http://svnbook.red-bean.com/en/1.6/svn.ref.svn.c.switch.html).

inputs/bien2_traits/TraitObservation/map.csv: Remapped Source to sourceType

mappings/VegCore.htm: Regenerated from wiki. Documentation has been added on how to choose term names (https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/VegCore#Naming) and how to form globally unique ID values (https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/VegCore#Forming-IDs). Source and Specimen terms have been renamed to be self-explanatory and unambiguous (the DwC equivalents remain as synonyms). Short definitions of Source terms have been added to explain the differences between them. Source, Specimen, and Collection terms have been shortened according to the new instructions for choosing preferred term names (https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/VegCore#Naming).

mappings/VegCore-VegBIEN.csv, inputs/*/*/map.csv: Applied term renamings from the new dynamically generated Veg+-VegCore.csv, which reflects the current state of the data dictionary. (Permanently switching to the new Veg+-VegCore.csv will be a separate change.) Updates to VegCore term names that have occurred since the data dictionary was created are now able to take effect, which involves remapping and inferring units on several fields.

mappings/VegCore.csv: Regenerated from wiki

inputs/*/*/map.csv: Reverted special OMIT mappings for input columns that have the same name as a VegCore table and have not yet been mapped to a VegCore term

Added inputs/bien2_traits/