This flag limits the number of matches printed *per file*.

Closes #159

This is intended to correspond to C/C++ header files.

Fixes #186

Fixes #203

Specifically, it can be used when searching for patterns that start
with a dash.

Fixes #215

This was a subtle bug, but the big picture was that the smart case
information wasn't being carried through to the literal extraction in
some cases. When this happened, it was possible to get back an incomplete
set of literals, which would therefore miss some valid matches.

The fix to this is to actually parse the regex and determine whether
smart case applies before doing anything else. It's a little extra work,
but parsing is pretty fast.

Fixes #199

Also update compile script.

Fixes #128

Add parallel recursive directory iterator.

This adds a new walk type in the `ignore` crate, `WalkParallel`, which
provides a way for recursively iterating over a set of paths in parallel
while respecting various ignore rules.

The API is a bit strange, as a closure producing a closure isn't
something one often sees, but it does seem to work well.

This also allowed us to simplify much of the worker logic in ripgrep
proper, where MultiWorker is now gone.

adding .mak extension for makefile filetype.

adding .pdf filetype to available types.

adding cs filetype for ease of use.

Fixes #217

Add textile, org, creole, rdoc, wiki filetype

add asciidoc filetype and update markdown filetype

Add Gentoo info to the README

Added taskpaper as a file type

Add Agda and improve TeX ignore support

This was probably a transcription error when moving the ignore matcher
code out of ripgrep core. Specifically, the override glob matcher should
not ignore directories if they don't match.

Fixes #206