This removes ripgrep-specific code for filtering files that correspond to
stdout and instead uses the 'ignore' crate's functionality for doing the
same.
This commit undoes a work-around for a bug in Rust's standard library
that prevented correct file type detection on Windows in OneDrive
directories. We remove the work-around because we are moving to a
latest-stable Rust version policy, which has included this fix for a while
now.
ref #705, https://github.com/rust-lang/rust/issues/46484
This commit does the work to delete the old `grep` crate and effectively
rewrite most of ripgrep core to use the new libripgrep crates. The new
`grep` crate is now a facade that collects the various crates that make
up libripgrep.
The most complex part of ripgrep core is now arguably the translation
between command line parameters and the library options, which is
ultimately where we want to be.