bitsy-parser 0.65.6

# bitsy-parser

a library for parsing Bitsy game data.

the version number follows Bitsy itself, so version 0.65.* targets Bitsy 6.5.

## how to use

a simple example program:

```rust
extern crate bitsy_parser;
use std::{env, fs};
use bitsy_parser::game::Game;
use bitsy_parser::image::Image;

/// replaces the player avatar with a smiley face.
fn main() {
    let input_file = env::args().nth(1)
        .expect("No input path specified. Usage: `smiley infile outfile`");
    let output_file = env::args().nth(2)
        .expect("No output path specified. Usage: `smiley infile outfile`");

    let mut game = Game::from(fs::read_to_string(input_file).unwrap());

    game.avatar.animation_frames = vec![
        Image {
            pixels: vec![
                0,0,1,1,1,1,0,0,
                0,1,1,1,1,1,1,0,
                1,1,0,1,1,0,1,1,
                1,1,0,1,1,0,1,1,
                1,1,1,1,1,1,1,1,
                1,1,0,1,1,0,1,1,
                0,1,1,0,0,1,1,0,
                0,0,1,1,1,1,0,0,
            ]
        }
    ];

    fs::write(output_file, &game.to_string())
        .expect("Failed to write to output file");
}
```

some more practical uses would be things like:

* remove duplicate tiles
* merge two Bitsy games together
* programmatically create Bitsy games
* a Bitsy game editor

## todo

* implement fonts!!
* implement Result return types on ::from functions so we can handle errors
* output sprites/avatar in such a way that ordering is preserved 
    (avatar seems to be somewhere in the sprites, 
    after any numeric-ID sprites and before any alphabetic-ID sprites...)
* check multi-line endings/dialogues

### tidy up

* refactor the more shonky bits to idiomatic rust