Optimize release size.

[yamafaktory]

Based on https://github.com/johnthagen/min-sized-rust.

Before

cargo build --release
du target/release/sd
2.0M    target/release/sd

After

cargo build --release
du target/release/sd
1.7M    target/release/sd

➡️ Another good optimization would be to strip the symbols from the binary:

strip target/release/sd 
du target/release/sd   
1.1M    target/release/sd

[chmln]

@yamafaktory thanks for your contribution :)

While small binary size is a noble goal, I believe that by optimizing for size during compilation we forego optimizing for performance.

Something like strip is nice but it's a lot of extra work to do this on our side. I'd rather wait for rust-lang/cargo#3483. Not to mention most Linux distros already do this automatically.

[yamafaktory]

Hi @chmln,
Thanks for the feedback! Should we close this PR?

[chmln]

@yamafaktory Yes. If you have any other ideas on how to improve sd, you're always welcome to open up an issue for discussion. Thanks again for putting in the time for the patch.