Add support for recording/running ref tests

Ref tests use a recording of the terminal protocol and a serialization
of the grid state to check that the parsing and action handling systems
produce the correct result. Ref tests may be recorded by running
alacritty with `--ref-test` and closing the terminal by using the window
"X" button. At that point, the recording is fully written to disk, and a
serialization of important state is recorded. Those files should be
moved to an appropriate folder in the `tests/ref/` tree, and the
`ref_test!` macro invocation should be updated accordingly.

A couple of changes were necessary to make this work:

* Ref tests shouldn't create a pty; the pty was refactored out of the
  `Term` type.
* Repeatable lines/cols were needed; on startup, the terminal is resized
* by default to 80x24 though that may be changed by passing
  `--dimensions w h`.
* Calculating window size based on desired rows/columns and font metrics
  required making load_font callable multiple times.
* Refactor types into library crate so they may be imported in an
  integration test.
* A whole bunch of types needed symmetric serialization and
  deserialization. Mostly this was just adding derives, but the custom
  deserialization of Rgb had to change to a deserialize_with function.

This initially adds one ref test as a sanity check, and more will be
added in subsequent commits. This initial ref tests just starts the
terminal and runs `ll`.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/meter.rs b/src/meter.rs
index 470f613c..b73c1004 100644
--- a/src/meter.rs
+++ b/src/meter.rs
@@ -20,7 +20,7 @@
 //!
 //! ```rust
 //! // create a meter
-//! let mut meter = Meter::new();
+//! let mut meter = alacritty::meter::Meter::new();
 //!
 //! // Sample something.
 //! {
@@ -29,7 +29,7 @@
 //!
 //! // Get the moving average. The meter tracks a fixed number of samles, and the average won't mean
 //! // much until it's filled up at least once.
-//! printf!("Average time: {}", meter.average());
+//! println!("Average time: {}", meter.average());
 
 use std::time::{Instant, Duration};