Use DSN instead of project name in sentry.properties

[sregg]

Currently our sentry.properties file contains the project name in defaults.project.
This is quite brittle as someone can change the project name in sentry.com (true story...)
It be great if we can use the DSN rather than the name for identification.

[HazAT]

Cool feature request but it's unlikely we will do this in this form right now.
We were thinking about revamping the sentry.properties files in general but this is still in the future.