Miscellaneous build / tidy fixes.

Cargo.lock

@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "accountable-refcell"
 version = "0.2.0"
@@ -1171,9 +1173,9 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.27.2"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "754b69d351cdc2d8ee09ae203db831e005560fc6030da058f86ad60c92a9cb0a"
+checksum = "1db8599a9761b371751fbf13e076fa03c6e1a78f8c5288e6ab9467f10a2322c1"
 dependencies = [
  "cssparser-macros",
  "dtoa-short",
@@ -5214,7 +5216,6 @@ dependencies = [
  "precomputed-hash",
  "servo_arc",
  "smallvec 1.6.1",
- "thin-slice",
  "to_shmem",
  "to_shmem_derive",
 ]