Add project*.api.php for hook documentation

Yes, please. ;) Thanks!

I tried to search the places where hooks are:

$ egrep -nr "(module_invoke|drupal_alter)" .
./project.inc:451:      $output = module_invoke('cvs', 'show_messages');
./project.inc:551:  drupal_alter('project_page_link', $all_links, $node);
./legacy_paths/project_legacy_paths.module:78:  $sort_methods = module_invoke_all('project_sort_methods', 'methods');
./release/project-release-private-download.php:175:module_invoke_all('project_release_download', $nid, $path, $user->uid);
./release/includes/release_node_form.inc:29:      module_invoke_all('exit');
./CHANGELOG.txt:168:#376458 by Dave Reid: Changed hook_project_page_link_alter() to be invoked via drupal_alter() instead of project_page_link_alter() and swapped the order of parameters to be consistent with other alter hooks.

So, here is a first patch that only indicate the function names and the places.

Am I missing hooks?

Heh, I started adding a project.api.php for the new hooks I added as part of #69556: move "cvs access" tab into project, make it generic. ;) Yes, you're missing a ton of hooks, but I don't have time to detail them all right now (I have to run). But, I'll get back to you on this ASAP. Thanks!