Enrollment agent certificate store location

[nilsbehlen]

It is probably preferred to have the enrollment agent cert used by the service to be in the users store.
ISignerCertificate::Initialize has a bool parameter to switch between machine and user context. So we could also make this configurable.
However, from experience the user that installs and therefore runs the service would create the enrollment agent certificate while doing so in the users store.

[nilsbehlen]

implemented in 1.0.1.
User store is now the default.