Allow configuring the amount of time before the "Last save" notification

[a7x492]

I think its 15 minutes, but hard-coded. Saving takes a long time so I'd like to configure this to 30 minutes or even one hour.

[realSquidCoder]

a fix for this is in the works. the next version of the save reminder will let you configure the time and in the future there will hopefully be a config menu