shelve: repo['.'] is not a wctx but a pctx

Don't confuse hackers!
mq: repo['.'] is not a wctx, repo[None] is

The parameters passed to subrepo.submerge are confusing anyway.
shelve: introduce secret option for using fixed date for temporary commit

Using a fixed date makes hashes stable and makes debugging simpler. The date
and hashes of this changeset are normally not exposed.
tests: make unshelve tests more tricky - don't depend on size change

One reason shelve and largefiles doesn't work could be rapidly changing standin
files. Prove that shelve in general doesn't have problems with that.
statichttp: respect localrepo _restrictcapabilities

The static http repository was doing his own filtering of capability ignoring
the filtering done in the local repo main class. This led to static http using
the current draft of bundle2. We now apply both.

--HG--
extra : rebase_source : a46cb7d7e5701adb7ad9429e374ced93bcf79be2
bundle2: use discard to remove bundle2 cap

caps.remove('bundle2') was throwing an exception if bundle2 wasn't present in
the capabilities. This was causing test-static-http.t to hang. Let's just use
discard, so we don't get an exception.
http: reuse authentication info after the first failed request (issue3567)

[This was applied in 181108726ea5 but backed out again in af02783dea65 because
of Python 2.4 issues. This edition and test-http.t works with Python 2.4.]

Context: mercurial access to repository server with http access, and this
server is protected by basic auth.

Before patch:

* mercurial try an anonymous access to server, server return 401 response and
  mercurial resend request with login / password information

After patch:

* mercurial try an anonymous access to server, server return
  401 response. For all next requests, mercurial keep in memory this
  information (this server need basic auth information).

This patch reduce the number of http access against mercurial server.

Example, before patch:

10.10.168.170 - - [25/Oct/2013:15:44:51 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:44:52 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:00 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:01 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:03 +0200] "GET /hg/testagt?cmd=batch
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:04 +0200] "GET /hg/testagt?cmd=batch
HTTP/1.1" 200 42 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:06 +0200] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:07 +0200] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 200 61184 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:09 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:10 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 15 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:12 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:12 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 - "-" "mercurial/proto-1.0"

Example after patch:

10.10.168.170 - - [28/Oct/2013:11:49:14 +0100] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:15 +0100] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:17 +0100] "GET /hg/testagt?cmd=batch
HTTP/1.1" 200 42 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:19 +0100] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 200 61184 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:22 +0100] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 15 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:24 +0100] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 - "-" "mercurial/proto-1.0"

In this last example, you can see only one 401 response.

--HG--
extra : rebase_source : 6731087708a4a697ee7874e40bc862291c1d0658
revlog: deal with chunk ranges over 2G on Windows (issue4215)

Python uses a C long (32 bits on Windows 64) rather than an ssize_t in
read(), and thus has a 2G size limit. Work around this by falling back
to reading one chunk at a time on overflow. This approximately doubles
our headroom until we run back into the size limit on single reads.

--HG--
branch : stable
extra : rebase_source : cb2322a9c49fcaaac5e7a32afd48c9659c6fd415
merge with stable