Use libdraw: add Xft and fallback-fonts support to graphics lib

- libdraw, util: add drw.{c,h}, util.{c,h} and update code.
- libdraw: fix drw_rect(): use w and h parameter.
- libdraw: print errstr if last character in string was ":" (sbase).
- libdraw: drw_clr_free() allow valid free(NULL).
- config.def.h: set default font to monospace.
- cleanup() on exit.
- LICENSE: update license string for dmenu -v to 2015.
- LICENSE: add myself to LICENSE

drw.h

@@ -0,0 +1,74 @@
+/* See LICENSE file for copyright and license details. */
+#define DRW_FONT_CACHE_SIZE 32
+
+typedef struct {
+	unsigned long pix;
+	XftColor rgb;
+} Clr;
+
+typedef struct {
+	Cursor cursor;
+} Cur;
+
+typedef struct {
+	Display *dpy;
+	int ascent;
+	int descent;
+	unsigned int h;
+	XftFont *xfont;
+	FcPattern *pattern;
+} Fnt;
+
+typedef struct {
+	Clr *fg;
+	Clr *bg;
+	Clr *border;
+} ClrScheme;
+
+typedef struct {
+	unsigned int w, h;
+	Display *dpy;
+	int screen;
+	Window root;
+	Drawable drawable;
+	GC gc;
+	ClrScheme *scheme;
+	size_t fontcount;
+	Fnt *fonts[DRW_FONT_CACHE_SIZE];
+} Drw;
+
+typedef struct {
+	unsigned int w;
+	unsigned int h;
+} Extnts;
+
+/* Drawable abstraction */
+Drw *drw_create(Display *dpy, int screen, Window win, unsigned int w, unsigned int h);
+void drw_resize(Drw *drw, unsigned int w, unsigned int h);
+void drw_free(Drw *drw);
+
+/* Fnt abstraction */
+Fnt *drw_font_create(Drw *drw, const char *fontname);
+void drw_load_fonts(Drw* drw, const char *fonts[], size_t fontcount);
+void drw_font_free(Fnt *font);
+void drw_font_getexts(Fnt *font, const char *text, unsigned int len, Extnts *extnts);
+unsigned int drw_font_getexts_width(Fnt *font, const char *text, unsigned int len);
+
+/* Colour abstraction */
+Clr *drw_clr_create(Drw *drw, const char *clrname);
+void drw_clr_free(Clr *clr);
+
+/* Cursor abstraction */
+Cur *drw_cur_create(Drw *drw, int shape);
+void drw_cur_free(Drw *drw, Cur *cursor);
+
+/* Drawing context manipulation */
+void drw_setfont(Drw *drw, Fnt *font);
+void drw_setscheme(Drw *drw, ClrScheme *scheme);
+
+/* Drawing functions */
+void drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int empty, int invert);
+int drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *text, int invert);
+
+/* Map functions */
+void drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h);