Make textcomp package register with textmacros automatically.

[dpvc]

This PR causes the textcomp package to add itself to the textmacros packages automatically. In order to allow it to work with \require{textcomp} (and to work better with the Lab), we do this through the config() function of the configuration rather than setting it via options. This is because when \require{textcomp} is processed, its dependecies are loaded and added to the configuration first, then textcomp is added. Because textmacros is a dependency, it will be added and configured before textcomp adds to the textmacros.packages if it is placed in the options.textmacros.packages configuration option. Here, using config(), we know that textmacros will already be configured, so we can add to the textConf configuration directly.

It may be possible to have \require collect the config() methods from the dependencies and run them after all the initialization is done, but I didn't want to make that big a change here. This should the job for now.

[zorkow]

Question on priority. Otherwise looks fine.

[zorkow]

Is there a reason for the priority?

[dpvc]

It was so that the base configuration is done first and then others that override anything in it don't need to specify their own priorities. But I think that the packages may be processed in reverse order, which means I should make this 10 instead.

[dpvc]

Just checked, and this does mean text-base will have its init() and config() methods called before the other configurations. So that means the default priority of 5 will put others after this, without having to set the priority.