New STJR Intro and related changes (resolves #202)

Closes #202

See merge request STJr/SRB2!1132

(cherry picked from commit 3437b0690a3f4278e3ecc657102a126a3e2f3d13)

(cherry picked from commit 0d57ba1d02c5bde2ab22a71d21a95849b21e9539)

SteelT authored 4 years ago and James R. committed 4 years ago

(cherry picked from commit cb9004e4cfa94251ab0d31f19fee187fc4e9abcc)

(cherry picked from commit 7a05a8acf73ac0f012135339447c9a935e3b7939)

Make the scene time be 5 seconds long max

Use the standard fade which is much shorter in length.

Detect which system the Makefile is running on to compile for

See merge request STJr/SRB2!1123

Use WARNINGMODE by default

See merge request STJr/SRB2!1122

Change the code a bit so less magic numbers.

Fix Ringslinger weapon ring penalty missnapment

See merge request STJr/SRB2!1120

Fix bug where SRB2 would check size of disk from current directory instead of srb2home

See merge request STJr/SRB2!1121

Fix lingering issues with the http-mserv merge

See merge request STJr/SRB2!1117

This should work for mingw and linux so far.

(cherry picked from commit ef2bff6383b16385f9874e1c9c6b66c9df794f5b)

Add a menu option for showjoinaddress; disable it by default

See merge request STJr/SRB2!1115

Hopefully that fixes that one bug with weird filesize issues too

REMOVE THE LAST OF CV_ALLCAPS

See merge request STJr/SRB2!1116