Initialize Delta accounts on plugin load

We don't yet configure any of the accounts, but we're set up to manage
several accounts simultaneously in the same plugin instance, using
delta's built-in support for that.

Cargo.lock

@@ -2309,6 +2309,16 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "os_pipe"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb233f06c2307e1f5ce2ecad9f8121cffbbee2c95428f44ea85222e460d0d213"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "ouroboros"
 version = "0.9.5"
@@ -2606,7 +2616,9 @@ dependencies = [
  "lazy_static",
  "log",
  "openssl",
+ "os_pipe",
  "purple-rs",
+ "serde",
 ]
 
 [[package]]