Add ability to set ANSI italics

This is not widely supported - it may not work for some users.
Add ability to set ANSI italics

This is not widely supported - it may not work for some users.
Preserve colour themes after :e
Merge remote-tracking branch 'origin/color-repl' into color-repl
Merge pull request #496 from david-christiansen/color-repl

Add ability to set ANSI italics