Merge branch 'es/blame-L-breakage'

Merge branch 'es/blame-L-breakage'

The refactoring made for parsing "-L" option recently to support
"git log -L" seems to have broken "git blame -L X,-5" to show 5
lines leading to X.

* es/blame-L-breakage:
  blame-options.txt: explain that -L <start> and <end> are optional
  blame-options.txt: place each -L option variation on its own line
  t8001/t8002 (blame): add blame -L :funcname tests
  t8001/t8002 (blame): add blame -L tests
  t8001/t8002 (blame): modernize style
  line-range: fix "blame -L X,-N" regression