Trim all trailing whitespace

The `.editorconfig` file in this repo is configured to trim all trailing
whitespace regardless of whether the line is modified.

Trims all trailing whitespace in the repository to make the codebase easier
to work with in editors that respect `.editorconfig`.

`git blame` becomes less useful on these lines but it already isn't very useful.

Commands:

```
find . -type f -name '*.h' -exec sed --in-place 's/[[:space:]]\+$//' {} \+
find . -type f -name '*.c' -exec sed --in-place 's/[[:space:]]\+$//' {} \+
```

engine/studio.h

@@ -1,9 +1,9 @@
 /***
 *
 *	Copyright (c) 1996-2002, Valve LLC. All rights reserved.
-*	
-*	This product contains software technology licensed from Id 
-*	Software, Inc. ("Id Technology").  Id Technology (c) 1996 Id Software, Inc. 
+*
+*	This product contains software technology licensed from Id
+*	Software, Inc. ("Id Technology").  Id Technology (c) 1996 Id Software, Inc.
 *	All Rights Reserved.
 *
 *   Use, distribution, and modification of this source code and/or resulting
@@ -93,7 +93,7 @@ Studio models are position independent, so the cache manager can move them.
 
 // motion flags
 #define STUDIO_X			0x0001
-#define STUDIO_Y			0x0002	
+#define STUDIO_Y			0x0002
 #define STUDIO_Z			0x0004
 #define STUDIO_XR			0x0008
 #define STUDIO_YR			0x0010
@@ -118,7 +118,7 @@ Studio models are position independent, so the cache manager can move them.
 #define STUDIO_SNAP			0x0002	// do not interpolate between previous animation and this one
 #define STUDIO_DELTA		0x0004	// this sequence "adds" to the base sequences, not slerp blends
 #define STUDIO_AUTOPLAY		0x0008	// temporary flag that forces the sequence to always play
-#define STUDIO_POST			0x0010	// 
+#define STUDIO_POST			0x0010	//
 #define STUDIO_ALLZEROS		0x0020	// this animation/sequence has no real animation data
 #define STUDIO_BLENDPOSE		0x0040   	// to differentiate GoldSrc style blending from Source style blending (with pose parameters)
 #define STUDIO_CYCLEPOSE		0x0080	// cycle index is taken from a pose parameter index
@@ -132,7 +132,7 @@ Studio models are position independent, so the cache manager can move them.
 #define STUDIO_LIGHT_FROM_ROOT	0x8000	// get lighting point from root bonepos not from entity origin
 
 // autolayer flags
-#define STUDIO_AL_POST		0x0001	// 
+#define STUDIO_AL_POST		0x0001	//
 #define STUDIO_AL_SPLINE	0x0002	// convert layer ramp in/out curve is a spline instead of linear
 #define STUDIO_AL_XFADE		0x0004	// pre-bias the ramp curve to compense for a non-1 weight,
 					// assuming a second layer is also going to accumulate
@@ -185,7 +185,7 @@ typedef struct studiohdr_s
 
 	// offset to the first hitbox chunk
 	int32_t		hitboxindex;
-	
+
 	// the number of sequences
 	int32_t		numseq;
 
@@ -217,7 +217,7 @@ typedef struct studiohdr_s
 	int32_t		skinindex;
 
 	// the number of bodyparts
-	int32_t		numbodyparts;		
+	int32_t		numbodyparts;
 
 	// offset to the first bodypart
 	int32_t		bodypartindex;
@@ -285,7 +285,7 @@ typedef struct
 } studiohdr2_t;
 
 // header for demand loaded sequence group data
-typedef struct 
+typedef struct
 {
 	// the model signature
 	int32_t		id;
@@ -491,7 +491,7 @@ typedef struct
 } mstudioaimatbone_t;
 
 // bone controllers
-typedef struct 
+typedef struct
 {
 	// bone affected by this controller
 	int32_t		bone;
@@ -521,7 +521,7 @@ typedef struct
 
 	// the hitbox minimum and maximum extents
 	vec3_t		bbmin;
-	vec3_t		bbmax;		
+	vec3_t		bbmax;
 } mstudiobbox_t;
 
 typedef struct
@@ -847,7 +847,7 @@ typedef struct mstudioanim_s
 } mstudioanim_t;
 
 // animation frames
-typedef union 
+typedef union
 {
 	struct
 	{
@@ -917,7 +917,7 @@ typedef struct
 typedef struct
 {
 	uint8_t		weight[4];
-	int8_t		bone[4]; 
+	int8_t		bone[4];
 } mstudioboneweight_t;
 
 // skin families
@@ -969,7 +969,7 @@ typedef struct
 // vec3_t	boundingbox[model][bone][2];		// complex intersection info
 
 // meshes
-typedef struct 
+typedef struct
 {
 	// can be interpreted as the number of triangles in the mesh
 	int32_t		numtris;
@@ -988,7 +988,7 @@ typedef struct
 } mstudiomesh_t;
 
 // triangles
-typedef struct 
+typedef struct
 {
 	// index into vertex array
 	int16_t		vertindex;