Document additional configuration properties

[infotexture]

@georgebina reported:

The documentation for the configuration.properties file lists a few properties but from Configuration.java it looks like there are also entries like print_transtypes, plugin.[name].dir and parser.[format]=[value]

The existing topics in the Configuration properties section of the Parameter Reference should be updated to cover the missing properties, explain how properties files are used internally by the toolkit, and clarify the difference between configuration properties and argument properties that users can set at transformation time.

We should also consider extending this section to cover not only configuration properties, but also include information on how users can use property files to specify transformation parameters by passing a property file as an argument to the dita command:

dita -propertyfile file

Load all properties from a file. Properties specified with the -D option take precedence.

[jelovirt]

Note that configuration properties and argument parameters are not necessarily the same, i.e. some configuration properties cannot be set as arguments, and the -propertyfile argument does not override the configuration file properties.

[infotexture]

Right, I think these are the sorts of things that should be clarified (which properties can be set where, which take precedence if the same ones are defined in different places, etc.).

[infotexture]

NOTE: A tutorial on “Setting DITA-OT parameters with .properties files” is one of the proposals in #37.