Adding DBUtil specs doc.

Specifications/DBUtil API.md

+### Database Utilities API
+
+This describes the API of the top level database interface. 
+
+You may be interested in the large schema diagram: [Large schema png file](Specifications/Originals/Schema Diagram.png)
+
+There is an interactive schema web site: [Schema web site](http://shannonvm.village.virginia.edu/~twl8n/schema_spy_output/)
+
+### Table of contents
+
+[Multiple names, alternate names, components](#multiple-names-alternate-names-components)
+
+[How dates are stored](#how-dates-are-stored)
+
+[How versioning works](#how-versioning-works)
+
+[Foreign key related records](#foreign-key-related-records)
+
+[Vocabulary table history and rationale](#vocabulary-table-history-and-rationale)
+
+[Vocabulary separate SQL file](#vocabulary-separate-sql-file)
+
+[Common fields and their meaning](#common-fields-and-their-meaning)
+
+[Identical text tables](#identical-text-tables)
+
+[Geographic authority](#geographic-authority)
+
+
+### New DBUtil and initialization
+
+When creating a DBUtil object, you must supply the application user credentials in the form of the numberic
+user id and numeric role.
+
+DBUtil will automatically internally mint new version and constellation main_id as necessary. For batch
+inserts you should create a single DBUtil object and use it for all inserts of every record in the
+batch. Passing in a constellation with no ID or version and asking for an "insert" operation will result in a
+new ID being minted. A new version will be minted if none exists. If a version exists, it will be used for all
+operations during the life of the DBUtil object. This is intentional. While the database is not appreciably
+effected by minting large numbers of versions, it does make the data harder for humans to read and debug. 
+
+### Constellation ID discovery
+
+This mechanism needs work. DBUtil needs a constellation ID in order to read a constellation from the
+database. Presumably, some function will exist in DBUtil that takes some constraints and returns a list of
+constellation ID.
+
+In the future we will support reading old versions of a constellation. In that case, discovery must return the
+constellation ID as well as version number. At that time, readConstellation() will need an update to take a
+version number argument. Low level SQL code already takes version number.
+
+
+### Reading and writing constellations
+
+Constellation insert, update, or delete is controlled by the getOperation() of the constellation and each
+component object. To save a constellation, call writeConstellation() with the constellation object, a string
+for status, and a string for the history note. To retrieve a constellation, call readConstellation() with
+constellation ID (aka main_id, $mainID).
+
+Current implementation of readConstellation() only supports reading the most recent version. Requirements for
+reading old versions are incomplete, but could be a simple as supplying readConstellation() with a version
+number. 
+
+Status is a (more or less?) controlled vocabulary. Examples include: 'published', 'needs review', 'rejected',
+'being edited', 'bulk ingest'.
+
+
+```
+    public function writeConstellation($cObj, $status, $note)
+
+    public function readConstellation($mainID)
+```
+
+### Utility functions
+
+A number of functions exist in DBUtil for testing.