Let ui.pl log to a file
Implement account and SIM saving in Net::Limesco.
Fix account validation in Net::Limesco: don't give an error if the response code was 204 (No Content), that's a fine result.
Implement SIM validation in Net::Limesco.
Move account_to_str() function to Net::Limesco so it can be used elsewhere.
Nicely align the accounts without markers with those that do have markers, and with those that have the CONFIRMATION_IMPOSSIBLE marker.
Sort accounts case insensitively.
Add SIP settings, porting date, activation invoice ID and last monthly fees invoice to SIM shower window.
Implement SIM updating and Account updating, using the "u" or "e" keys.
Don't show the allocate_simbox if there are no unallocated SIMs.
Don't show the allocate_simbox again if it is already open.