Make attach process the same for Client and Manager

[ChristianBeer]

Currently the Manager uses a 4 step process to attach the Client to a project:

1. The User selects or enters a URL in the Attach project Wizard. The Manager makes a GET request to URL/get_project_config.php to fetch the master_url
2. The Manager tells the Client to attach to master_url
3. The Client fetches the content of master_url to scrape the scheduler_url from the HTML
4. The Client uses the scheduler_url to actually attach to the project

This is a problem when a User uses boinccmd to attach to a project on the commandline since he/she has to use the master_url or there will be an annoying message in the Client logfile each time the Client connects to the project. The process using boinccmd instead of the Manager looks like this:

1. The User calls boinccmd --project_attach URL account_key
2. The boinccmd tool tells the Client to attach to URL
3. The Client treats URL as the master_url and fetches the content of URL to scrape the scheduler_url from the HTML
4. The Client uses the scheduler_url to actually attach to the project

The problem is that there are projects that have a different master_url and website_url. For example Einstein@home redirects all web requests to https://einsteinathome.org but for historical reasons the master_url in https://einsteinathome.org/get_project_config.php is still http://einstein.phys.uwm.edu/ (because it is not possible to just change this without all users re-attaching to the project).

For consistency either the boinccmd tool or the Client itself should do a request to URL/get_project_config.php like the Manager does.

[RichardHaselgrove]

This issue came up in https://boinc.berkeley.edu/forum_thread.php?id=12722, opened by Gary Roberts. Gary is one of our most experienced helpdesk volunteers (a moderator at Einstein@Home since the year dot), but even he was stumped by account manager problems and error messages.

I've had a good prod around all three current account managers, and I'd suggest the following.

• Going forward, both boinccmd and BOINC Manager should validate project urls via get_project_config.php, including urls supplied by an account manager.
• Existing account manager administrators should verify periodically that they are properly issuing MASTER urls as specified in https://boinc.berkeley.edu/trac/wiki/AccountManagement. I found one that wasn't, in the first session of testing. The documentation needs strengthening to reinforce this point.
• It's very unclear on the face of BOINC Manager that an account manager is in use, and I can't find a url to link back to the management page anywhere in BOINC Manager. The activity of an account manager is only explicit in the Advanced View version of the Tools menu.

Given that we lack a mechanism for recalling old versions of BOINC, I'd suggest that both the first two points are necessary. I'll leave the third point in the hands of the interface designers and translators, but I'd suggest an additional 'Visit AM site' button on the Projects tab, between the 'Command' and 'Project' button frames.