support custom header name for source maps

[graingert]

This change is

[graingert]

I think this is the minimum change to support HTTP basic auth: You set token_name to "Authorization" and you set token to 'Basic ' + base64.b64encode('%s:%s' % (urllib.quote(username), urllib.quote(password)))

I want basic auth support because its difficult (read without compiling modules) to configure nginx to compare a token securely.

The config:

location/static/source-maps/{set$auth_realmRestricted;if($http_x_sentry_token='redacted'){set$auth_realmoff;}auth_basic$auth_realm;auth_basic_user_file/etc/nginx/.htpasswd;expiresmax;add_headerCache-Control"private";}

Isn't secure because the token can be discovered using a timing attack, however basic_auth does hashing (therefore secure compare), salts and multiple access lists etc etc and is generally really handy for this sort of thing.

[mattrobenolt]

Hey @graingert, I'm ok with this change. Sorry for the delay. I'm going to pull this and test it manually to make sure everything is correct against current master.

[mattrobenolt]

@graingert I'm closing this in favor of #4630 since it needed a few things to make it fully work. :)