tests/test-execute-bit.t

debugcommands: support sending HTTP requests with debugwireproto

We implement an action that can issue an HTTP request. We can define
headers via arguments and specify a file to use for the HTTP request
body.

The request uses the HTTP peer's opener, which is already configured
for auth, etc. This is both good and bad. Good in that we get some
nice behavior out of the box. Bad in that some HTTP request headers
are added automatically.

Differential Revision: https://phab.mercurial-scm.org/D2841

#require execbit

  $ hg init
  $ echo a > a
  $ hg ci -Am'not executable'
  adding a

  $ chmod +x a
  $ hg ci -m'executable'
  $ hg id
  79abf14474dc tip

Make sure we notice the change of mode if the cached size == -1:

  $ hg rm a
  $ hg revert -r 0 a
  $ hg debugstate
  n   0         -1 unset               a
  $ hg status
  M a

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg id
  d69afc33ff8a
  $ test -x a && echo executable -- bad || echo not executable -- good
  not executable -- good