i18n: replace gnu unifont with droid sans font

- Static variables can be initialized with constants only.
- Removed bunifont.ttf.c from datafiles -- it's not actually a
  data file. Unicode font loading stuff is not in blenkernel/font.c
- Allocate as much memory for unzipped data as it's needed.
  Default read chunk is 512Kb.
- Fixed regression (or just a typo) in setting utf locale.
- Default locale set to en_US:en works fine now.
- Commented put Nepali language in user preferences -- it's
  not supported by current droid font and imo it's better to
  have nice font for languages we actually have translation for
  rather than allowing to choose more languages in user preferences.

source/blender/windowmanager/intern/wm_init_exit.c

@@ -342,7 +342,6 @@ extern void free_anim_copybuf(void);
 extern void free_anim_drivers_copybuf(void); 
 extern void free_fmodifiers_copybuf(void); 
 extern void free_posebuf(void); 
-extern void free_datatoc_bunifont_ttf(void);
 
 /* called in creator.c even... tsk, split this! */
 void WM_exit(bContext *C)
@@ -381,7 +380,6 @@ void WM_exit(bContext *C)
 	BIF_freeTemplates(C);
 	
 	free_ttfont(); /* bke_font.h */
-	free_datatoc_bunifont_ttf(); /* bunifont.ttf.c */
 	free_openrecent();
 	
 	BKE_freecubetable();