Fixed extreme slow loading time on some clients
- This was done by replacing 'file.Exists(luafile, "LUA")' with a custom implementation. See: https://github.com/Facepunch/garrysmod-issues/issues/5674

Improved load times on some cases and updated wirelink support.

- Removed 'collectgarbage( "collect" )' calls to improve load times on some cases.
- Updated Wirelink detection to upcomming Wiremod changes.

Fixed fonts being duplicated and removed math.randomseed calls.

Fixed songs loops and allow URLs from admin radios

- Fixed songs ending with "sound stopped" on song switch.
- Radios owned by admins will allow all URLs as admins are a trusted sources of media. ConVar: `sv_streamradio_url_whitelist_trust_admin_radios 0/1`, Enabled by default.

Fixed Lua errors, clean up and added a GUI skin

- Fixed Lua errors:
-- lua/streamradio_core/tool.lua:480: attempt to call method 'GetMode' (a nil value)
-- lua/entities/base_streamradio.lua:486: attempt to index upvalue 'LIBUtil' (a nil value)
- Fixed global scope pollution
- Some code clean up and new glualint config
- Added a new GUI skin preset called "Steam Original"

Updated help texts, changed whitelist logic

- Updated help and description texts to reflect the latest changes. Spelling and grammar fixes.
- Added info buttons and new options to admin panel
- Updated help links in whitelisting errors
- CFC Whitelist and built-in whitelist logic are completely separated now
- Added ConVar `sv_streamradio_url_whitelist_enable_on_cfcwhitelist`. Built-in whitelist is disabled by default if CFC Whitelist is installed to improve radio usability. Use added ConVar to change this behavior. It's safe to change.

Fixes Lua error in VR and playback error screen

Fixes to "stopsound" and better whitelisting code

- Fixed "stopsound" concommand not working on radios.
- Added GUI cases and controls to resume radios stopped by "stopsound".
- Added context menu options for resuming radios stopped by "stopsound".
- Improved Dropbox support with CFC HTTP Whitelist.
- Improved URL checks for addon's whitelist.
- Improved URL checks for CFC HTTP Whitelist.
- Improved rendering performance of GUIs a bit..
- Refactored auto converters for URLs and removed dead YouTube code.
- Added max age of files (7 days) to the cache system. Older cache files are deleted.
- Moved the file cache location to "cache-sv" and "cache-cl" for server/client. The old cache directory is wiped.

Added Stream URL whitelisting, optimized netcode

- Added Stream URL whitelisting:
-- It is on by default, even for existing installs.
-- Can be changed in admin panel or via console `sv_streamradio_url_whitelist_enable 1/0`. Although, it is not recommended to turn it off.
-- Clients will ask the server if a URL is good. If it isn't, any attempt to play from it will result in error 1000 (`STREAM_ERROR_URL_NOT_WHITELISTED`). This will prevent radio abuse such as IP graping and other malicious intends. You can ask an admin to have it whitelisted on the server.
-- Whitelists is based on the installed playlist.
-- Added several ways for admins to quickly add new whitelist entries to so-called quick-whitelists. Quick-whitelists are playlist files too.
-- Removed `sv_streamradio_allow_customurls`, as it has been replaced with the new whitelisting.
-- Added integration for CFC HTTP Whitelist to this addon's whitelist. If CFC whitelists an URL, the addon will whitelist it for your client too (but not necessarily for others).

- Improved info texts a bit.
- Optimized networking to have less entity.__index calls.
- Added better URL and path sanitation.
- Fixed potential race conditions when loading files or streams.

- Fixed E2 wirelinks not working.