Two-letter driver names ('pg' instead of 'postgres')

[neilotoole]

In keeping with sq's general goal of terseness, sq should prefer short driver names. As in:

# Prefer this:
$sq add 'pg://user:pass@localhost/sakila`

# Over existing mechanism:
$ sq add 'postgres://user:pass@localhost/sakila'

Similarly my for mysql, ms for sqlserver/mssql, sl for sqlite3, etc. The sq add cmd should still accept the long variants, and sq should be able to read the long variants from config (e.g. if the user manually edits sq.yml).

[kobayashi]

Hello,

I have just added PR #93 for this. Please let me know if there is something to change or the other way.

[neilotoole]

After several looks into this, it's 👎.

Much of the pain has gone away due to implementation of sq's excellent shell completion. But the main vote against this is that the connection string URLs would be non-canonical, making sense only to sq, but not to any other programs or libraries. It's not worth the pain.