Merge branch 'nd/attr-match-optim-more'

Merge branch 'nd/attr-match-optim-more'

Start laying the foundation to build the "wildmatch" after we can
agree on its desired semantics.

* nd/attr-match-optim-more:
  attr: more matching optimizations from .gitignore
  gitignore: make pattern parsing code a separate function
  exclude: split pathname matching code into a separate function
  exclude: fix a bug in prefix compare optimization
  exclude: split basename matching code into a separate function
  exclude: stricten a length check in EXC_FLAG_ENDSWITH case