Make the store plugins more introspectable

Directly register the store classes rather than a function to build an
instance of them.
This gives the possibility to introspect static members of the class or
choose different ways of instantiating them.

1 files changed, 1 insertions, 0 deletions

diff --git a/result b/result
new file mode 120000
index 000000000..af7bbb6da
--- /dev/null
+++ b/result
@@ -0,0 +1 @@
+/nix/store/9pqfirjppd91mzhkgh8xnn66iwh53zk2-hello-2.10
\ No newline at end of file