Ignore all IO errors during completion

Misc

A full refresh must be performed when last hint is removed.

BackTab (Shift-Tab) on both unix and windows
F1...F5 on linux console
Ctrl-Space on windows

Prepare 2.0.1 release

Misc

(cherry picked from commit 17ae324d6d9ff7cc1f200eec73d8d9e831f8bb26)

(cherry picked from commit ecf4d1413f0a099bd8afe4bda5ea8dbd8b363f9f)

(cherry picked from commit 88b690ec718286c646822e4b89f28e667fbd4d54)

(cherry picked from commit 4d3da773f2e24625566ebe0a469fd31bbee38649)

Fix one clippy warning

Use into() instead of casting to c_ulong because of different types in some targets

Mark highlight_dynamic_prompt as deprecated

And fix example.

Prepare 2.0 release

Prepare 2.0 release

Modify Editor Config #137

Add a way to get the helper