Update offscreen-gl-context and rust-webvr

This deduplicates libloading and removes one crate that depends on something related to serde.
servo · nox · May 24, 2017 · May 24, 2017 · 00196344d8e37f75db1073afa62f0a1179aba374
commit 00196344d8e37f75db1073afa62f0a1179aba374
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/servo-tidy.toml b/servo-tidy.toml
@@ -34,7 +34,6 @@ num = []
 # Ignored packages with duplicated versions
 packages = [
   "bitflags",
-  "libloading", # Conflicting version is only used at build-time by geckolib.
 ]
 # Files that are ignored for all tidy and lint checks.
 files = [