Improve profile handling

[JHooverman]

As shown in the screen-shot, QupZilla creates a separate network cache for each different qt-/ qtwebkit-versions per profile. After upgrading qt or qtwebkit QupZilla creates a new networkcache-folder without deleting the old one.

In my current used profile custom_en_US I have already nine networkcache-folders, consuming about 350 MB storage - altogether I have about 15 different profiles in use.
If #1570 is taken into consideration there is a lot of harddisk space unnecessarily wasted.

Will it be possible to let QupZilla remove unneeded folders automatically?

[ChristianTacke]

Could you also please consider to move the network cache in a proper cach location, like the one returned by QStandardPaths::writableLocation(QStandardPaths::CacheLocation)

This helps a lot with backup (people can exclude ~/.cache/ from their backup). Or people can just clean up old files there. Which would help the Bug Opener as well.

[pmattern]

I just tried to reproduce this on Arch Linux to no avail.
To test, cf8e983 was compiled against Qt 5.6.1, several QupZilla profiles were created on a new (Linux) user profile and used for a while. Next the same commit was compiled against Qt 5.7.0 and the same QupZilla profiles were used for another while. Only directories like

~/.cache/qupzilla/<profile>/Cache/

comprising cached files only and

.config/qupzilla/profiles/<profile>/
.config/qupzilla/profiles/<profile>/GPUCache
.config/qupzilla/profiles/<profile>/thumbnails
.config/qupzilla/profiles/<profile>/Service Worker
.config/qupzilla/profiles/<profile>/Service Worker/ScriptCache
.config/qupzilla/profiles/<profile>/Service Worker/ScriptCache/index-dir
.config/qupzilla/profiles/<profile>/Service Worker/Database
.config/qupzilla/profiles/<profile>/databases
.config/qupzilla/profiles/<profile>/adblock
.config/qupzilla/profiles/<profile>/extensions
.config/qupzilla/profiles/<profile>/Local Storage

could be seen. So in particular nothing specific to the Qt version in use and no directory networkcache either.

So am I missing something or is this whole thing specific to a particular platform or even obsolete?