Fix markup error.
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 3.x 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.