[Open Assets] srb2dl - SRB2 Content Downloader CLI

• Added SRB2 VR's source code and its compiled binaries for Windows and Linux,
• Changed SRB2 Kart VR's source code link to proper branch,
• Changed link to SRB2 Persona .exe file,
• Added SRB2 Persona AppImage,
• Made more colored text for some messages.

• Added SRB2 Persona and its source code, GoldenTails' SRB2 AppImages, Lonsfor's SRB2 Kart, SRB2 Kart Moe Mansion AppImages to Custom Builds.

• Added PandaSRC's SRB2 2.1 Legacy version and John Frostfox's SRB2 NetPlus,
• Fixing SRB2 Uncapped Plus source code name.

• Added SRB2 2.1 builds, source code and SRB2 archived versions to --old option.

• Fixing issue of Curl (since version 7.79) canceling downloading some files and leaving warning message,
• Added SRB2 archived versions (including the original SRB) and SRB2 Uncapped Plus to SRB2 Build category,
• Fixing links to SRB2 Android Port and SRB2Kart Moe Mansion,
• Fixing issue with not properly displaying page numbers, when selecting files and then returning to the list of addons,
• Removing some unnecessary lines of code and other small fixes.

This update provides new feature to this script. Now you can download content that is archived in mb.srb2.org, which is useful for older versions of SRB2 and SRB2Kart. To access obsolete mods, you need to type srb2dl --old.

DEMO:

Other updates includes:
- Added support for MacOS,
- Added support for SOC files,
- Default installation to "/usr/local/bin" path on Linux, if system has it, otherwise it is "/usr/bin",
- Changed "-a" option to "-u",
- Some text and code fixes,

Minor fixes to content's updated date and download queue, when the same file is selected. External tutorials included how to install dependencies for Linux and Windows.