Modify the command-line shell to print a warning when using an in-memory
database.
In the command-line shell, on the banner, warn about the use of a
transient in-memory database in bold red text.
On unix, make the "transient in-memory database" text bold, but not red.
Leave the text read on windows.
Add the ".save" command as an alias for ".backup".  Improvements to the
way font changes are implemented on the in-memory database warning.
Fixes to the "editline" support in the command-line shell.
Updates to the command-line shell.  Simplify the banner message.  Add the
".save" command as an alias for ".backup".  When starting with no arguments,
include a banner message warning that the database is transient and in-memory
and mention the ".open" command.
Increase the version number to 3.8.4
Sync with trunk.  Bring in the command-line shell updates and the new 3.8.4
version number.