run-test: replace backslashes in TESTDIR

This may cause troubles in MSYS on Windows.
run-tests: don't add python lines to expected dict

For test input lines of *.t files starting with '  >>> ', the code block for
'  >>> '

609:        if l.startswith('  >>> '): # python inlines
610:            after.setdefault(pos, []).append(l)

was (unsurprisingly) executed, but because there was an "if" instead of an
"elif" on the condition "l.startswith('  ... ')", program execution proceeded
to line 636

635:        elif l.startswith('  '): # results
636:            # queue up a list of expected results
637:            expected.setdefault(pos, []).append(l[2:])

due to the fact that if l starts with '  >>> ' it also starts with '  '.

The net effect was that python command lines in *.t files were (surprisingly)
also added to the "expected" dict.

This caused no externally observable bad behavior, as the "expected" dict was
not consulted for these lines.
tests: introduce c-style conditional sections in .t tests

This makes it possible to have conditional sections like:

#if windows
  $ echo foo
  foo
#else
  $ echo bar
  bar
#endif

The directives and skipped sections are treated like comments, so don't
interleave them with commands and their output.

The parameters to #if are evaluated while preparing the test by passing them
over to hghave. Requirements can thus be negated with 'no-' prefix, and
multiple requirements must all be true to return true.
test-paths.t: enable for Windows using #if

If the no-msys exit at the beginning is removed, the test fails on Windows with
MSYS with:

  --- C:\Users\adi\hgrepos\hg-main\tests\test-paths.t
  +++ C:\Users\adi\hgrepos\hg-main\tests\test-paths.t.err
  @@ -24,7 +24,7 @@
     expand = $TESTTMP/a/foo/bar (glob)
     $ SOMETHING=/foo hg paths
     dupe = $TESTTMP/b (glob)
  -  expand = /foo/bar
  +  expand = c:/MinGW/msys/1.0/foo/bar
     $ hg paths -q
     dupe
     expand

caused by http://www.mingw.org/wiki/Posix_path_conversion .
help: fix search with `-k` option in non-ASCII locales

Keyword search in help (introduced in 497deec204d1 and a17983680f12 by Augie
Fackler) tries to translate already translated strings, which results in
Unicode errors in gettext when non-ASCII locale is used. Also command
descriptions should be translated before searching there (thanks to FUJIWARA
Katsunori for pointing this out and actual fix), (issue3482).
test-clone-failure: enable for Windows using #if
tests: roll test-clone-failure.t into test-clone.t
base85: cast Py_ssize_t values to int (issue3481)

If it outputs a nonsense value, no harm done, it was nonsense to start with.
tests: roll test-commit-copy.t into test-commit.t
test-revset: enable for Windows

In MSYS, the test fails like this if the hghave exit at the beginning is
removed:

  --- C:\Users\adi\hgrepos\hg-main\tests\test-revset.t
  +++ C:\Users\adi\hgrepos\hg-main\tests\test-revset.t.err
  @@ -58,7 +58,7 @@
     $ hg co 3
     2 files updated, 0 files merged, 0 files removed, 0 files unresolved
     $ hg branch /a/b/c/
  -  marked working directory as branch /a/b/c/
  +  marked working directory as branch a:/b/c/
     (branches are permanent and global, did you want a bookmark?)
     $ hg ci -Aqm"5 bug"

  @@ -252,7 +252,7 @@
     2 a-b-c-
     3 +a+b+c+
     4 -a-b-c-
  -  5 /a/b/c/
  +  5 a:/b/c/
     6 _a_b_c_
     7 .a.b.c.
     $ log 'children(ancestor(4,5))'

due to the posix path conversion done by MSYS globally, as explained here

  http://www.mingw.org/wiki/Posix_path_conversion

The solution is a bit lame, but it is simple and works: don't use strings that
look like '/a/b', in order not to trigger the path magic done by MSYS.

So, if we can agree not to insist on testing branch names starting with '/',
then this relatively simple patch makes the test pass both on Windows with MSYS
and Linux.
help: format extension lists using RST

This change is a move towards generating all help text as a list of strings
marked up with RST.
help: format command and option list help using RST

This patch changes the function which generates help text about commands and
options to use RST formatting. Tables describing options have been formatted
using RST table markup for some time already, so their appearance does not
change. Command lists, however, change appearance.

To format non-verbose command lists, RST field list markup was chosen, because
it resembles the old format:

<http://docutils.sourceforge.net/docs/user/rst/quickref.html#field-lists>

In the old (hand-coded) format of non-verbose command lists, the left column is
12 characters wide. Our minirst implementation formats field lists with a left
column 14 characters wide, so this patch changes the appearance of help output
correspondingly:

<http://markmail.org/message/krl4cxopsnii7s6z?q=mercurial+reinert+from:%22Olav+Reinert%22&page=2>

The minirst markup most closely resembling the old verbose command lists is
definition lists. But using it would cause a blank line to be inserted between
each command definition, making the output excessively long, and no more
useful than before. To avoid this, I chose to use field lists also for verbose
command help, resulting in output like this example:

 add           add the specified files on the next commit
 annotate, blame
               show changeset information by line for each file
 clone         make a copy of an existing repository
 commit, ci    commit the specified files or all outstanding changes
 diff          diff repository (or selected files)
 export        dump the header and diffs for one or more changesets
 forget        forget the specified files on the next commit
 init          create a new repository in the given directory
 log, history  show revision history of entire repository or files
 merge         merge working directory with another revision
 phase         set or show the current phase name
 pull          pull changes from the specified source
 push          push changes to the specified destination
 qdiff         diff of the current patch and subsequent modifications
 qinit         init a new queue repository (DEPRECATED)
 qnew          create a new patch
 qpop          pop the current patch off the stack
 qpush         push the next patch onto the stack
 qrefresh      update the current patch
 remove, rm    remove the specified files on the next commit
 serve         start stand-alone webserver
 status, st    show changed files in the working directory
 summary, sum  summarize working directory state
 update, up, checkout, co
               update working directory (or switch revisions)

This change is a move towards generating all help text as a list of strings
marked up with RST.
help: format all output using RST

This change is the last patch needed to implement help text generation based
only on formatting a single text object marked up with RST.
help: fix keyword search output for extension commands

This patch fixes the help keyword search "hg help -k" to show correct results
in the section listing extension commands.
tests: roll test-copy2.t into test-copy.t
test-tags: enable for Windows

It turns out that MSYS does have a chmod.exe, but it has no effect. So, the
inserted "#if unix-permissions" is somewhat redundant, as the test would pass
without it as well: it would simply write the tag cache, despite what the
comment says.

But I'm actually in favor of inserting the #if, as it makes it clearer what's
going on.
perf: add a benchmark for revrange
revset: drop unreachable code
revset: turn dagrange into a function
revset: implement dagrange directly

This is much faster than the older implementation (~8x).