Add comment for boolean arguments

Include std headers right after <kazv-defs.hpp>

Resolve change request

In D194#3576, @tusooa wrote:

] wc -l src/l10n/cmn-Hans/100-ui.ftl
413 src/l10n/cmn-Hans/100-ui.ftl
] wc -l src/l10n/en/100-ui.ftl   
435 src/l10n/en/100-ui.ftl

seems there are still a lot of things missing in mandarin

Do you mean the progress bar in notifications? I'm about to disable it in all cases since it won't appear in Microsoft Windows. ProgressBar(QML) and progress text is sufficient.

Added comment on why loops cannot be used directly on m_d->cacheJobs

• Fixed the problem that kazv cannot be closed when cached files

In D176#3265, @tusooa wrote:

test that if it is cancelled, the file will not be found on disk.

In D178#3268, @tusooa wrote:

How is it "less buggy"? What bug does it fix?

Add tests for KazvFile and KazvSaveFile

Rebase onto servant