* Added some XXX comments.
* Changed the way text nodes are handled so that adjacent text nodes are merged.
* Changed the way original keys are kept so that they work across flattening, rounding, and that there is no 'coses: original keys' hash getting in the way.
* Fixed a bug whereby empty arrays and hashes caused extraneous iterations in <set> elements.
* Removed some redundant scalar()s.
* Added support for group membership levels (now you can be a normal member, as before, but also a group op or a group admin) -- this affected the user data source, the mysql data source, and the user service.
* Added a getFieldsHierarchically() method to the user data source.
* Added a getFieldsByCategory() method to the user data source.
* Fixed a typo in some of the SQL in the rights management part of the MySQL user data source.
* Added support in the arguments input module for treating the arguments as dot-delimited trees and returning a specific branch.
* Added support in the passwords service for encrypting a specific password.
* Added a getFieldByID() method to the user service.
* Made the groups in the user service be indexed by both ID and Name.
* Implemented the user preferences component.
* Changed FileStrings so that it doesn't have to be updated every time the file string format changes. The format is now one line per piece of metadata, then a blank line, then the string data. If additional metadata is added later then this will automatically support it.
* Renamed the dataSource.strings service to dataSource.strings.customised, and renamed its get() method to getCustomisedString().
* Changed the semantics of dataSource.strings.customised so that it no longer looks for a default string if it can't find a customised one (and thus removed getDefaultString).
* Abstracted the Generic output module even more. It now consists of output.generic (a service instance with its own constructor) and dataSource.strings (a pure service), the latter of which is a wrapper around dataSource.strings.customised and dataSource.strings.defaults.
* Updated Coses to work with the new dataSource.strings insterface.
* Removed the test app DataSource::ConsoleStrings and DataSource::HTTPStrings files, since they were redundant with the default output files.
* Removed all the default strings in the CosesEditor and Login components since they are pretty pointless.
* Factored out the call to dump() in the GenericOutputs module.
* Changed setString in the MySQL string data source so that it will now add a blank string (it used to delete the string if it was blank, but that meant that it was not possible to customise strings away).
* Added a piece of metadata to strings: their version number.
* Updated the customised string data source stubs to mention the version data now stored with all strings
* Added a getAllStringVersions method to the customised strings data source which returns all the string names and their version numbers.
* Made the customised strings data source check the version number of every string in its database during setupInstall to make sure that they are all up to date, version-wise. If any are out of date, the user is notified.
* Added support for the new version column to the MySQL version of the customised string data source.
* Updated the increasingly misnamed CosesEditor to support the versioned strings stuff.
* Factored out some code in the CosesEditor.
* Added version information to all default strings. All default strings are now at version 1.
* Fixed a typo in a FileStrings dump statement.
* Fixed the calls to setProgress in the MySQL user and strings data sources and in the user field factory to use the correct syntax (a parsable dotted string instead of unlocalisable plain English).
* Updated the Generic output module's documentation to match what now happens.
