documentation for development

[frenkiboy]

A detailed documentation for development which will track the most recent changes - i.e. when a .in file appears, that we know where it is used, and why, and that it appeared.

[rekado]

The canonical list of files containing placeholders is in the configure.ac file. Running the configure script instantiates all of these .in templates by replacing the placeholder variables.

Is any other documentation needed?