Add rust-encoding as a submodule.

Upstream: https://github.com/lifthrasiir/rust-encoding
Servo’s fork: https://github.com/mozilla-servo/rust-encoding

As of this writing, upstream’s master branch targets Rust 0.8,
and its rust-0.9-pre branch targets Rust master.
Servo uses a Rust version in-between those.
I pushed a rust-servo branch to our fork
that backports from rust-0.9-pre.

.gitmodules

@@ -106,3 +106,7 @@
 [submodule "src/support/http/rust-http"]
 	path = src/support/http/rust-http
 	url = https://github.com/mozilla-servo/rust-http
+[submodule "src/support/encoding/rust-encoding"]
+	path = src/support/encoding/rust-encoding
+	url = https://github.com/mozilla-servo/rust-encoding.git
+	branch = rust-servo

configure

@@ -498,6 +498,7 @@ CFG_SUBMODULES="\
     support/alert/rust-alert \
     support/azure/rust-azure \
     support/css/rust-cssparser \
+    support/encoding/rust-encoding \
     support/harfbuzz/rust-harfbuzz \
     support/http/rust-http \
     support/hubbub/libhubbub \

mk/sub.mk

@@ -50,6 +50,15 @@ DEPS_rust-azure += \
 	rust \
 	$(NULL)
 
+DEPS_rust-cssparser += \
+	rust-encoding \
+	rust \
+	$(NULL)
+
+DEPS_rust-encoding += \
+	rust \
+	$(NULL)
+
 DEPS_glfw-rs += \
 	glfw \
 	rust \

src/support/encoding/rust-encoding

@@ -0,0 +1 @@
+Subproject commit 2c486a34dedba1faace3de641e0ace103c7f3145