[Open Assets] srb2srv - SRB2 Server CLI

Features:

• Included SRB2 Classic/SRB2 Legacy Master Server,
• Flags for SRB2 Classic/SRB2 Legacy: -dc, --dedicatedclassic, -dl, --dedicatedlegacy, -fc, --filterclassic, -fl, --filterlegacy, -l, --legacy, -lc, --classic, -sc, --serverclassic, -sl, --serverlegacy, -ic, --ipclassic, -il, --iplegacy

Fixes:

• Fixed issue with some server data producing "\u0000" code from SRB2 MS JSON file that causes "warning: command substitution: ignored null byte in input" for gawk command when choosing server from SRB2 MS.

Other:

• Updated README.md.

- Fixed issue of not exact filtering server by its name (espaecially with the same label like "[EU]") with filter selection on list,
- Fixed issue of server name with hyphen and other characters messing with Master Server server list.

Fixes:
- Fixed issue of unavailable server list after SRB2 Master Server backend update,
- Fixed issue with proper displaying SRB2 Kart and Ring Racers Master Server list caused by unreachable IPs.

Feature:
- Added "Modified" column for SRB2 and Ring Racers.

Features:
- Added support to Dr. Robotnik's Ring Racers with flags -dr, --dedicatedringracers, -fr, --filterringracers, -ir, --ipringracers, -kr, --ringracers, -sr, --serverringracers.

Fixes:
- Replaced to working link to the list of servers for SRB2 Kart from Master Server.

Other:
- Updated README.md.

- Fixed issues with filtering servers when selecting SRB2 Master Server room,
- Filter query is now case insensitive.

Features:
- Added options -f/--filter and -fk/--filterkart to filter list of SRB2/SRB2Kart servers from Master Server,
- Added option -r/--room to list SRB2 by room from Master Server (issue #1),
- SRB2 and SRB2KART environment variables with value "flatpak" support other SRB2/SRB2Kart Flatpaks, which requires entering "flatpak [SRB2/SRB2Kart Application ID]" for all Flatpaks, for example SRB2="flatpak org.srb2.SRB2" or SRB2KART="flatpak org.srb2.SRB2Kart".

Other:
- Updated README.md,
- Added Map to details of SRB2Kart server.

• Added option to disable automatic restart of server after error. To turn off, set environment variable "export NOSRB2SRVLOOP=1".

• Added options to join SRB2/SRB2Kart server from entered IP.
• Added SRB2MAINCFG, SRB2CFG, SRB2KARTMAINCFG, SRB2KARTCFG for setting paths to game's configuration files.

• Added error message, if there is no connection to Master Server,
• Fixed issue of not displaying number of active players in Battle mode, when selecting server from SRB2 Kart Master Server list,
• Added missing color to text, when choosing SRB2 Kart servers,
• Changed position of countdown to restart own server after error.

• Fixed issues of paths to addons not to be displayed from file list or not to be loaded at all in some cases after the last update,
• Fixed displaying unusual output,
• Fixed issue of not to be able to enter commands from dedicated server.