Initial implementation of Azure Functions for Rust.

This commit is the initial implementation of the Azure Functions for Rust
prototype.

It supports writing Azure Functions that bind with:

* HTTP trigger bindings
* HTTP output bindings
* Timer bindings

.gitignore

@@ -1,10 +1,16 @@
 # Generated by Cargo
 # will have compiled files and executables
-/target/
+**/target
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
 Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+# Example generated script root directories
+examples/http/root
+examples/timer/root
+
+.vscode/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "lib/protobuf"]
+path = lib/protobuf
+url = git@github.com:Azure/azure-functions-language-worker-protobuf.git