Currently, when unlimited scrollback is used, the files are stored in
/tmp. As noted in the bug report, this can cause issues on some
distros. The default is still /tmp but the user can selected to use
a location in their $HOME folder (QStandardPaths::CacheLocation).
This is somewhat a WIP. Allowing for the changes to take effect
immediately appears to be a gigantic mess to get to work.
CCBUG: 173283
So if someone notices later some Qt header is included in the form
of "#include <Class>" instead of the more common form of "#include
<Module/Class>", do not rush changing it.
REVIEW: 105819
Some people may not realize that when using 'unlimited scrollback' the
scrollback is on the hard drive unencrypted. The recent libvte
'security' report brought this issue up.
REVIEW: 104452
This make EditProfileDialog and HistorySizeDialog reuse the same
widget, instead of duplicating each other in its own code or .ui file.
HistorySizeDialog is now just a simple container of HistorySizeWidget
