Comparison to the fallible_collections crate

[jschwe]

Hi,

I've been loosely following the vec_fallible_allocation RFC and saw you closed the RFC and published this crate.

I've previously encountered (but not used) the fallible_collections crate.
Would it be possible to add a section to the Readme comparing this crate with the fallible_collections crate (well, probably only the Vec portion of it). The exposed API seems to be quite similar, so I'm wondering what the main differences are.

[dpaoliello]

Great idea!
I'll change the readme with more details, but to summarize: this crate is specifically designed for situations where #[cfg(no_global_oom_handling)] is enabled: other crates like fallible_collections won't work in those environments as they call methods like push in their implementations, which don't exist when that cfg is enabled.