Dummy dependencies are not required to execute a subproject automatically for providing a program, nor do you need to explicitly call subproject() to do that. A `[provide]` section in the wrap file is enough.
Also switch the wrap file style to use spaces around `=` which is the canonical style used by wrapdb now.
Do not use my personal workspace.
While we're developing gi-docgen it's better to have it as part of our build.
