pretty unicode banner #14733
Description
Using unicode, one can get the banner to look like that:
┌────────────────────────────────────────────────────────────────────┐
│ Sage Version 5.8, Release Date: 2013-03-15 │
│ Type "notebook()" for the browser-based notebook interface. │
│ Type "help()" for help. │
└────────────────────────────────────────────────────────────────────┘
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Warning: this is a prerelease version, and it may be unstable. ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
Apply:
- attachment: trac_14733_banner_unicode_color.patch to the Sage library
- attachment: trac_14733_version_regexp.patch to the root repository
Depends on #14559
CC: @sagetrac-tmonteil
Component: user interface
Keywords: banner, unicode
Author: Frédéric Chapoton
Reviewer: Volker Braun, William Stein
Merged: sage-5.12.beta1
Issue created by migration from https://trac.sagemath.org/ticket/14733