Fix papersprites being rotated incorrectly in Software when viewing them on the flipped side

See merge request STJr/SRB2!1770

Add angle field to linedef_t

See merge request STJr/SRB2!1602

Prevent Hangsters from sliding across the ceiling

Closes #787

See merge request !1766

Fix Ideya Capture sometimes stealing extra spheres

See merge request STJr/SRB2!1768

Do not reload every texture when adding a wad

See merge request !1725

Drop shadow fake floor/ceiling fix

See merge request !1638

Fix Minus & debris' reverse gravity behavior

See merge request !1764

Show overall grade emblem requirement of a multi-mare NiGHTS stage in SP pause menu

Closes #71

See merge request !1762

Remove drop shadow from badnik explosions, give drop shadows to Metal and flickies

Closes #218

See merge request !1761

Make S_IVSP and  S_THUNDERCOIN_SPARK fullbright

See merge request !1755

Make P_SpawnGhostMobj ghosts properly copy spritestuff2 (!1257) variables

See merge request !1741

Level platter name improvements

See merge request !1730

Also clean up redundant "startingspheres" variable

Fix typo in linux-only compilation flag

See merge request !1759

Remove MODID check from hooklib to fix compile issue (resolves #809)

See merge request !1758

Fixes #71

- Added A_SetShadowScale
- Added A_ShadowScream which combines the above with A_Scream, used for 
badnik explosions
- Gave flickies drop shadows

Update Nightopians & other state changes

See merge request STJr/SRB2!1744

Tutorial scenery

See merge request STJr/SRB2!1722

Fix #805

Closes #805

See merge request STJr/SRB2!1757

Spawn MT_RAY when attempting to spawn MT_NULL

Closes #801 and #800

See merge request STJr/SRB2!1751

2022

See merge request STJr/SRB2!1754

Fix warning when compiling with NONET=1

See merge request STJr/SRB2!1753

Fix perfstats failing to compile with NOHW=1

See merge request STJr/SRB2!1728