Add simple C bindings and some (horrid) code to generate them

Author: TheBlueMatt

Cargo.toml

@@ -3,6 +3,7 @@
 members = [
     "lightning",
     "lightning-net-tokio",
+    "lightning-c-bindings",
 ]
 
 # Our tests do actual crypo and lots of work, the tradeoff for -O1 is well worth it

c-bindings-gen/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "c-bindings-gen"
+version = "0.0.1"
+authors = ["Matt Corallo"]
+edition = "2018"
+
+[dependencies]
+syn = { version = "1", features = ["full", "extra-traits"] }
+proc-macro2 = "1"
+
+# We're not in the workspace as we're just a binary code generator:
+[workspace]