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

pm_shared/pm_defs.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
@@ -100,12 +100,12 @@ typedef struct playermove_s
 	vec3_t		velocity;		// Current movement direction.
 	vec3_t		movedir;		// For waterjumping, a forced forward velocity so we can fly over lip of ledge.
 	vec3_t		basevelocity;	// Velocity of the conveyor we are standing, e.g.
-	
+
 	// For ducking/dead
 	vec3_t		view_ofs;		// Our eye position.
 	float		flDuckTime;	// Time we started duck
 	qboolean		bInDuck;		// In process of ducking or ducked already?
-	
+
 	// For walking/falling
 	int		flTimeStepSound;	// Next time we can play a step sound
 	int		iStepLeft;
@@ -157,13 +157,13 @@ typedef struct playermove_s
 	// world state
 
 	// Number of entities to clip against.
-	int		numphysent;    
+	int		numphysent;
 	physent_t		physents[MAX_PHYSENTS];
 
 	// Number of momvement entities (ladders)
 	int		nummoveent;
 	// just a list of ladders
-	physent_t		moveents[MAX_MOVEENTS];	
+	physent_t		moveents[MAX_MOVEENTS];
 
 	// All things being rendered, for tracing against things you don't actually collide with
 	int		numvisent;
@@ -181,7 +181,7 @@ typedef struct playermove_s
 	struct movevars_s	*movevars;
 	vec3_t		player_mins[4];
 	vec3_t		player_maxs[4];
-	
+
 	// Common functions
 	const char	*(*PM_Info_ValueForKey) ( const char *s, const char *key );
 	void		(*PM_Particle)( const float *origin, int color, float life, int zpos, int zvel );
@@ -193,7 +193,7 @@ typedef struct playermove_s
 	void		(*PM_StuckTouch)( int hitent, pmtrace_t *ptraceresult );
 	int		(*PM_PointContents)( float *p, int *truecontents /*filled in if this is non-null*/ );
 	int		(*PM_TruePointContents)( float *p );
-	int		(*PM_HullPointContents)( struct hull_s *hull, int num, float *p );   
+	int		(*PM_HullPointContents)( struct hull_s *hull, int num, float *p );
 	pmtrace_t		(*PM_PlayerTrace)( float *start, float *end, int traceFlags, int ignore_pe );
 	struct pmtrace_s	*(*PM_TraceLine)( float *start, float *end, int flags, int usehulll, int ignore_pe );
 	int			(*RandomLong)( int lLow, int lHigh );

pm_shared/pm_info.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

pm_shared/pm_movevars.h

@@ -1,6 +1,6 @@
 //========= Copyright (C) 1996-2002, Valve LLC, All rights reserved. ============
 //
-// Purpose: 
+// Purpose:
 //
 // $NoKeywords: $
 //=============================================================================
@@ -21,8 +21,8 @@ struct movevars_s
 	float	accelerate;        // Acceleration factor
 	float	airaccelerate;     // Same for when in open air
 	float	wateraccelerate;   // Same for when in water
-	float	friction;          
-	float	edgefriction;	   // Extra friction near dropofs 
+	float	friction;
+	float	edgefriction;	   // Extra friction near dropofs
 	float	waterfriction;     // Less in water
 	float	entgravity;        // 1.0
 	float	bounce;            // Wall bounce value. 1.0
@@ -35,13 +35,13 @@ struct movevars_s
 	float	rollangle;
 	float	rollspeed;
 	float	skycolor_r;			// Sky color
-	float	skycolor_g;			// 
+	float	skycolor_g;			//
 	float	skycolor_b;			//
 	float	skyvec_x;			// Sky vector
-	float	skyvec_y;			// 
-	float	skyvec_z;			// 
+	float	skyvec_y;			//
+	float	skyvec_z;			//
 	int	features;		// engine features that shared across network
-	int	fog_settings;	// Global fog settings (packed color+density) 
+	int	fog_settings;	// Global fog settings (packed color+density)
 	float	wateralpha;	// World water alpha 1.0 - solid 0.0 - transparent
 	float	skydir_x;		// skybox rotate direction
 	float	skydir_y;		//