Replace some new *Field with *Field::create()

Specifically intended to change new TreeDropdownField with TreeDropdownField::create but also replaced a few others as well.  This allows class replacement of TreeDropdownField in order to extend its functionality without having to override HTMLEditorField.
Merge pull request #2623 from tractorcow/pulls/3.2-form-naming-fixes

BUG 3.2 Issues with CMSForm not consistently respecting new form naming scheme
Merge pull request #2612 from AlphaCactus/patch-1

Replace new *Field with *Field::create()
Added "be inclusive" sentence to contrib docs
API New Database abstraction layer. Ticket #7429
Database abstraction broken up into controller, connector, query builder, and schema manager, each independently configurable via YAML / Injector
Creation of new DBQueryGenerator for database specific generation of SQL
Support for parameterised queries, move of code base to use these over escaped conditions
Refactor of SQLQuery into separate query classes for each of INSERT UPDATE DELETE and SELECT
Support for PDO
Installation process upgraded to use new ORM
SS_DatabaseException created to handle database errors, maintaining details of raw sql and parameter details for user code designed interested in that data.
Renamed DB static methods to conform correctly to naming conventions (e.g. DB::getConn -> DB::get_conn)
Added alter and drop to list of database write operations
Added 3.2 upgrade docs
FIXED Clarified behaviour of DataObject::get with a case-insensitive class name. Limit this test to MySQL for the sake of prudence.
Corrections to merge of files that have moved location.
Better use of filter over where in TreeDropdownField
Updated and replaced use of deprecated api
API DB naming requirements better conform to MySQL standard naming rules
Corrected deprecated DB::createDatabase API
Fixed array to string conversion in MemberAuthenticator::authenticate
API Prepared statement caching
API Option to allow for prepared statement emulation in PDO
API Added exec method to PDOConnector
BUG Added workaround and notice for check table commands failing using PDO in native mode
BUG Fixed issues with PDO running in native mode
API DBSchemaManager has 'notice' status flag for messages
PHP Optimisation
API Dropped DBQueryBuilder->format for performance reasons
API Optimised DataObject::hasOwnTableDatabaseField with static replacement and simpler implementation
Optimised DataObject::database_fields
Simplified DataQuery::ensureSelectContainsOrderbyColumns and DatabaseAdmin::cleanup to use more concise API
BUG Fixed incorrect cacheKey generation in DataObject::get_one
Better use of DataList::filter, ::byID, and ::byIDs
Reverted removal of "SELECT ... IN ..." syntax for ExactMatchFilter, which helps to generate simpler SQL for multiple comparisons
Less repetition of unnecessary calls to SS_Database::comparisonClause
Improved PHPDoc
Reverted change to DBQueryBuilder and re-implemented old behaviour with better code
Fixed issues with sort order of fixed fields (ClassName, Created, LastEdited) in queries.
Fixed issue with behaviour of sort order
BUG Fixed issue with composite fields in DataObject::write
PHPDoc additions
BUG Fixed issue with test subclasses of Member interfering with security checking in BasicAuthTest
Fixed scrutinizer issues