fix update when a locally added file match the target revision the dirstate entry for the added file wasn't updated. fix issue207

util.unlink should only catch OSError.

benoit asked for comment to make avoid of recursive repo clearer.

merge with crew.

support nested repositories. mercurial will not recurse into a subdirectory that contains a .hg directory. it is treated as a separate repository.

Don't use -u option for diff on SunOS, too. This makes the tests work without using GNU diff on Solaris 8.

run-tests: Use appropriate (that is: none) diff options on HP-UX.

Use the new format of setting tags in view extension (Debian bug #361897)

Never exit directly from commands.dispatch(), but pass return code to caller. Usually the caller is commands.run(). Some extensions still use sys.exit(), this is catched, too. Fixed wrong return statement in commands.recover() yielding a zero exit code.

Polished exception handling when importing extensions: - Warning about failed import is printed on one line. - For this warning the [extensions] section key is used, because the value doesn't have to be set. - Whan a --traceback is requested, exit immediately to not mix up problems when importing an extension with other problems.