More utility.py cleanup
Removed defaults section from tribler.conf
Renaming some functions
Removed ConfigReader
Removed speed getters/setters from Utility
Fix for changing speed limit using SettingsDialog
Fix missing import
Small fix for reading json strings from tribler.conf
Added get_free_random_port to Utility + set default videohttpport to -1
Revert "Added get_free_random_port to Utility + set default videohttpport to -1"

This reverts commit f40da93a3ecab97537b20c03bc35ce95eff590fd.
Revert "Small fix for reading json strings from tribler.conf"

This reverts commit fcaea3752b953861d020558fad0b58cff4a4688c.
Undo testing commits
Merge remote-tracking branch 'upstream/devel' into main_config

Conflicts:
	Tribler/Category/CategoryTester.py
	Tribler/Core/SessionConfig.py
	Tribler/Main/Dialogs/SaveAs.py
	Tribler/Main/Utility/utility.py
	Tribler/Main/vwxGUI/UserDownloadChoice.py
	Tribler/Main/vwxGUI/channel.py
	Tribler/Policies/SeedingManager.py
	Tribler/Utilities/configreader.py
	Tribler/Video/VideoPlayer.py
Showsaveas should not be in DownloadConfig
Small fix
Fix for DefaultDownloadConfig
Fix for torrent_id == -1 by Niels
Make I2I listenport configurable
Add locking to CallbackConfigParser
Removed DownloadRuntimeConfig + SessionRuntimeConfig