globset: polishing

This brings the code in line with my current style. It also inlines the
dozen or so lines of code for FNV hashing instead of bringing in a
micro-crate for it. Finally, it drops the dependency on regex in favor
of using regex-syntax and regex-automata directly.

Cargo.lock

@@ -130,12 +130,6 @@ dependencies = [
  "encoding_rs",
 ]
 
-[[package]]
-name = "fnv"
-version = "1.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
-
 [[package]]
 name = "glob"
 version = "0.3.1"
@@ -148,11 +142,11 @@ version = "0.4.13"
 dependencies = [
  "aho-corasick",
  "bstr",
- "fnv",
  "glob",
  "lazy_static",
  "log",
- "regex",
+ "regex-automata",
+ "regex-syntax",
  "serde",
  "serde_json",
 ]