Use clippy (#276)

* cton-util: fix some clippy unnecessary pass-by-value warnings

* clippy: ignore too many arguments / cyclomatic complexity in module

since these functions are taking args coming from the command line, i
dont think this is actually a valid lint, morally the arguments are all
from one structure

* cton-util: take care of remaining clippy warnings

* cton-reader: fix all non-suspicious clippy warnings

* cton-reader: disable clippy at site of suspicious lint

* cton-frontend: disable clippy at the site of an invalid lint

* cton-frontend: fix clippy warnings, or ignore benign ones

* clippy: ignore the camelcase word WebAssembly in docs

* cton-wasm: fix clippy complaints or ignore benign ones

* cton-wasm tests: fix clippy complaints

* cretonne: starting point turns off all clippy warnings

* cretonne: clippy fixes, or lower allow() to source of problem

* cretonne: more clippy fixes

* cretonne: fix or disable needless_lifetimes lint

this linter is buggy when the declared lifetime is used for another type
constraint.

* cretonne: fix clippy complaint about Pass::NoPass

* rustfmt

* fix prev minor api changes clippy suggested

* add clippy to test-all

* cton-filetests: clippy fixes

* simplify clippy reporting in test-all

* cretonne: document clippy allows better

* cretonne: fix some more clippy lints

* cretonne: fix clippy lints (mostly doc comments)

* cretonne: allow all needless_lifetimes clippy warnings

remove overrides at the false positives

* rustfmt

lib/filetests/src/lib.rs

@@ -3,6 +3,11 @@
 //! This crate contains the main test driver as well as implementations of the
 //! available filetest commands.
 
+#![cfg_attr(feature="cargo-clippy", allow(
+        type_complexity,
+// Rustfmt 0.9.0 is at odds with this lint:
+        block_in_if_condition_stmt))]
+
 #[macro_use(dbg)]
 extern crate cretonne;
 extern crate cton_reader;
@@ -44,7 +49,7 @@ type TestResult = Result<time::Duration, String>;
 /// Directories are scanned recursively for test cases ending in `.cton`. These test cases are
 /// executed on background threads.
 ///
-pub fn run(verbose: bool, files: Vec<String>) -> TestResult {
+pub fn run(verbose: bool, files: &[String]) -> TestResult {
     let mut runner = TestRunner::new(verbose);
 
     for path in files.iter().map(Path::new) {