qt: Backup former GUI settings on `-resetguisettings`

Pull Request #11338

State completed
Build time Total: 42 minutes
8 minutes for macOS
14 minutes for Windows
21 minutes for Linux
Platforms   
Start Date2017-09-17 05:23:33 UTC
Github#11338
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Author laanwj
Pull request head hashb28af386
Build styleThis pull request was built on top of current master
Build Log HEAD~65997004d9 Merge branch '2017_10_backup_resetguisettings' of https://github.com/laanwj/bitcoin into HEAD
b28af386a squashme: code style, doc
0f29983c8 squashme: guisettings.ini.bak
e278f86c5 Merge #11196: Switch memory_cleanse implementation to BoringSSL's to ensure memory clearing even with -lto
f725dbbfc squashme: add dst.clear to make sure that nothing stays behind
4e9dc85e0 qt: Backup former GUI settings on `-resetguisettings`