Fix warnings like:

tools.h:57:13: warning: inline function 'delay_force_time_out' declared but never defined

 inline void delay_force_time_out( Delay *delay );

             ^

tools.h:54:12: warning: inline function 'delay_timed_out' declared but never defined

 inline int delay_timed_out( Delay *delay, int ms );

            ^

tools.h:51:13: warning: inline function 'delay_reset' declared but never defined

 inline void delay_reset( Delay *delay );

Which ends up with this king of errors:

/builddir/build/BUILD/ltris-1.0.19/src/bowl.c:1353: undefined reference to `delay_timed_out'

/builddir/build/BUILD/ltris-1.0.19/src/bowl.c:1311: undefined reference to `delay_force_time_out'

diff -rup ltris-1.0.19.orig/src/sdl.h ltris-1.0.19/src/sdl.h

--- ltris-1.0.19.orig/src/sdl.h	2013-05-03 18:13:11.000000000 +0100

+++ ltris-1.0.19/src/sdl.h	2015-05-11 18:54:37.949653509 +0100

@@ -41,8 +41,8 @@ typedef struct {

 SDL_Surface* load_surf(char *fname, int f);

 SDL_Surface* create_surf(int w, int h, int f);

 void free_surf( SDL_Surface **surf );

-inline void lock_surf(SDL_Surface *sur);

-inline void unlock_surf(SDL_Surface *sur);

+extern void lock_surf(SDL_Surface *sur);

+extern void unlock_surf(SDL_Surface *sur);

 void blit_surf(void);

 void alpha_blit_surf(int alpha);

 void fill_surf(int c);

@@ -86,8 +86,8 @@ Font* load_font(char *fname);

 Font* load_fixed_font(char *fname, int off, int len, int w);

 void free_font(Font **sfnt);

 int  write_text(Font *sfnt, SDL_Surface *dest, int x, int y, char *str, int alpha);

-inline void lock_font(Font *sfnt);

-inline void unlock_font(Font *sfnt);

+extern void lock_font(Font *sfnt);

+extern void unlock_font(Font *sfnt);

 SDL_Rect last_write_rect(Font *fnt);

 int  text_width(Font *fnt, char *str);

@@ -132,14 +132,14 @@ Video_Mode* cur_video_mode();

 char** get_mode_names( int *count );

 int  set_video_mode( Video_Mode mode );

 void hardware_cap();

-inline void refresh_screen( int x, int y, int w, int h );

+extern void refresh_screen( int x, int y, int w, int h );

 void refresh_rects();

 void add_refresh_rect(int x, int y, int w, int h);

 int  wait_for_key();

 void wait_for_click();

-inline void lock_screen();

-inline void unlock_screen();

-inline void flip_screen();

+extern void lock_screen();

+extern void unlock_screen();

+extern void flip_screen();

 void fade_screen( int type, int ms );

 void take_screenshot( int i );

@@ -148,8 +148,8 @@ void take_screenshot( int i );

 SDL_Cursor* create_cursor( int width, int height, int hot_x, int hot_y, char *source );

 /* timer */

-inline int get_time();

-inline void reset_timer();

+extern int get_time();

+extern void reset_timer();

 #ifdef __cplusplus

 };

diff -rup ltris-1.0.19.orig/src/tools.h ltris-1.0.19/src/tools.h

--- ltris-1.0.19.orig/src/tools.h	2013-05-03 18:13:11.000000000 +0100

+++ ltris-1.0.19/src/tools.h	2015-05-11 18:48:11.099638130 +0100

@@ -33,7 +33,7 @@

 #define VEC_DIST( vec1, vec2 ) ( sqrt( ( vec1.x - vec2.x ) * ( vec1.x - vec2.x ) + ( vec1.y - vec2.y ) * ( vec1.y - vec2.y ) ) )

 /* compares to strings and returns true if their first strlen(str1) chars are equal */

-inline int strequal( char *str1, char *str2 );

+extern int strequal( char *str1, char *str2 );

 /* delete lines */

 void delete_lines( char **lines, int line_number );

@@ -45,16 +45,16 @@ typedef struct {

 } Delay;

 /* set delay to ms milliseconds */

-inline void delay_set( Delay *delay, int ms );

+extern void delay_set( Delay *delay, int ms );

 /* reset delay ( cur = 0 )*/

-inline void delay_reset( Delay *delay );

+extern void delay_reset( Delay *delay );

 /* check if time's out ( add ms milliseconds )and reset */

-inline int delay_timed_out( Delay *delay, int ms );

+extern int delay_timed_out( Delay *delay, int ms );

 /* set timer so that we have a time out next call of delay_timed_out() */

-inline void delay_force_time_out( Delay *delay );

+extern void delay_force_time_out( Delay *delay );

 /* return distance betwteen to map positions */

 int get_dist( int x1, int y1, int x2, int y2 );