Minor Grow scale corrections

See merge request KartKrew/Kart!605

Fix blockmap WILD inconsistency when it's not PIT_CheckThing

See merge request KartKrew/Kart!601

Tester text

See merge request KartKrew/Kart!603

Eggman Mark cinder fix

See merge request KartKrew/Kart!600

(Sloped ceilings are reversed and not sure what to do about it)

Makes slopes at a great enough steepness able to match the contrast of walls.

COMING SOON: Directional lighting & contrast modifier, as options for map header.

Fake contrast setting is no more

Makes skyboxes look better

Prevent rings from suddenly growing in size when a Grow player interacts with them, to match how using rings while grown or shrunk have them at mapobjectscale.

Follower angle lag + lookback

See merge request KartKrew/Kart!597

Trick threshold

See merge request KartKrew/Kart!599

Adjust steering lock after successful DI

See merge request KartKrew/Kart!602

* Show version/DEVELOP info on the title screen, not the top-level menu (necessary in advance of new-menus).
* Add TESTER/HOSTTESTER information to `version` command and title screen DEVELOP info.

An optimized error check was put into P_BlockThingsIterator for tmthing, but this meant that anything that was not using or even setting this variable (the supermajority of them) would exit after finding 1 thing in each block.

To keep this error check & keep it optimized, the PIT_ functions were expanded to three options instead of two: BMIT_CONTINUE lets the search continue. If used as the last mobj, it will return true when the iterator finishes. BMIT_ABORT ends the search and forces the iterator to return false.
BMIT_STOP ends the search and forces the iterator to return true.

* Allow colorisation types to not completely crowd each other out.
    * For example, it's possible for invincibility + grow to flicker Invincibility, Eggman mark, and grow colours if the conditions for each type of flash are true on different frames!

* This tilt is a *difference* between the axes, so a slight diagonal shouldn't intefere.

This value is closer to how the old value felt before the tracking was improved.

(not that it even uses the real color, buuut...)

(Why was angle being set again above this...)

- ANGLELAG lets you set how fast the followers swivel around. Default is 8*FRACUNIT, old behavior can be returned with FRACUNIT.
- Followers reverse their angle when you hold the lookback button.
- All lag values can't go below FRACUNIT instead of 1.

This reverts commit 0ce466e7.

This reverts commit 5ef78cbc.