tests/test-fastannotate-diffopts.t

import-checker: make stdlib path detection work in virtual environments

The previous logic tried to find the directory containing BaseHTTPServer, which
didn’t work as indended because it was only present on Python 2. Instead, the
argparse module is used now.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > fastannotate=
  > EOF

  $ hg init repo
  $ cd repo

changes to whitespaces

  $ cat >> a << EOF
  > 1
  > 
  >  
  >  2
  > EOF
  $ hg commit -qAm '1'
  $ cat > a << EOF
  >  1
  > 
  > 2
  > 
  > 
  > 3
  > EOF
  $ hg commit -m 2
  $ hg fastannotate -wB a
  0:  1
  0: 
  1: 2
  0: 
  1: 
  1: 3