Issue #20315: Removed support for backward compatibility with early 2.x versions.
Issue #20262: Warnings are raised now when duplicate names are added in the
ZIP file or too long ZIP file comment is truncated.
Issue #20311: select.epoll.poll() now rounds the timeout away from zero,
instead of rounding towards zero. For example, a timeout of one microsecond is
now rounded to one millisecond, instead of being rounded to zero.
Issue #20311: Try to fix the unit test, use time.monotonic() instead of
time.perf_counter()

Move also the unit test at the end.
Issue #20222: file is no longer a builtin in 3.x.
Issue #20122: Idlelib: Move tests in CallTips.py to test_calltips.py.
Issue #16655: Explain why Idle's test_calltips has 'fragile' tests of builtins.
fix deprecated-removed directive with sphinx 1.2
Issue #20301: Mention the correct KEY_* value as the default
for 'access' in winreg.DeleteKeyEx.  Already correct in the docs
function signature and docstring.  Noticed by Justin Foo.
Issue #2382: SyntaxError cursor "^" now is written at correct position in most
cases when multibyte characters are in line (before "^").  This still not
works correctly with wide East Asian characters.
Issue #16630: Make Idle calltips work even when __getattr__ raises.
Initial patch by Roger Serwy.
Issue #20246: Fix test failures on FreeBSD. Patch by Ryan Smith-Roberts.
Issue #17825: Cursor ^ is correctly positioned for SyntaxError and IndentationError.
Issue #16638: Include up to 5 docstring header lines (before first blank) in
Idle calltips. This is needed for builtins, such bytes (which is why 5).
Based on patch by Serhiy Storchaka.
Issue #20818: Remove code from idlelib.CallTipWindow.showtip that is now
completely redundant. After 16638 patch, CallTips.get_argspec trims over-long
signature strings as well as docstring lines.
Issue #20317: Don't create a reference loop in ExitStack