When we don't use an account anymore, the suggested way of doing this is to create an "archive" group and move the inactive account there. It's all good and well, but the problem is that this account will still show up in auto-complete and it's annoying because you sometimes don't remember that an account is archived and mistakenly refer to it in a transaction without noticing.
In this issue, we would add a "Inactive" checkbox to the account edit panel and when it it checked, the account wouldn't show up in auto-complete.
Also, this issue is somewhat related to #150
Add new "inactive" flag to accounts
Inactive flags don't show up in auto-completions.
Qt-only UI for now. Cocoa UI coming shortly.
Implement Cocoa UI for the new Inactive account flag