Don't try to determine interactivity if ui() called with interactive=False.
WSGI applications are not supposed to refer to sys.stdin. In ed6df6b1c29a,
hgweb and hgwebdir were fixed to pass interactive=False to their ui()'s, but
sys.stdin.isatty() was still called by the ui objects. This change makes sure
only the ui.fixconfig() method will call ui.isatty() (by making the
ui._readline() method, which is currently only called from ui.prompt(),
private). ui.fixconfig() is changed to let config files override the initial
interactivity setting, but not check isatty() if interactive=False was
specified in the creation of the ui.
% init
% setup
% delete an empty directory
empty_dir
Removing directory empty_dir
directory
r1
% delete an untracked directory
untracked_dir/untracked_file1
untracked_dir/untracked_file2
Removing file untracked_dir/untracked_file1
Removing file untracked_dir/untracked_file2
Removing directory untracked_dir
directory
r1
% delete an untracked file
untracked_file
Removing file untracked_file
directory
r1
% delete an untracked file in a tracked directory
directory/untracked_file
Removing file directory/untracked_file
directory
r1
% delete nested directories
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
% delete nested directories from a subdir
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
% delete only part of the tree
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
directory/untracked_file
% skip ignored files if --all not specified
directory
ignored
r1
ignored
Removing file ignored
directory
r1
% abort with missing files until we support name mangling filesystems
refused to run
untracked_file still around
untracked_file
refused to run
untracked_file still around
Removing file untracked_file
directory
r1
% skip excluded files
directory
excluded_file
r1
% skip files in excluded dirs
directory
excluded_dir
r1
file
% skip excluded empty dirs
directory
excluded_dir
r1
% skip patterns