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, 3 insertions, 3 deletions

diff --git a/src/index.rs b/src/index.rs
index 946e01fa..dc98be1e 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -21,7 +21,7 @@ use std::mem;
 use std::ops::{self, Deref, Add};
 
 /// Index in the grid using row, column notation
-#[derive(Debug, Clone, Default, Eq, PartialEq)]
+#[derive(Debug, Clone, Default, Eq, PartialEq, Serialize, Deserialize)]
 pub struct Cursor {
     pub line: Line,
     pub col: Column,
@@ -30,7 +30,7 @@ pub struct Cursor {
 /// A line
 ///
 /// Newtype to avoid passing values incorrectly
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Default, Ord, PartialOrd)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Default, Ord, PartialOrd, Serialize, Deserialize)]
 pub struct Line(pub usize);
 
 impl fmt::Display for Line {
@@ -42,7 +42,7 @@ impl fmt::Display for Line {
 /// A column
 ///
 /// Newtype to avoid passing values incorrectly
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Default, Ord, PartialOrd)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Default, Ord, PartialOrd, Serialize, Deserialize)]
 pub struct Column(pub usize);
 
 impl fmt::Display for Column {