Remove strsep() call

strsep() is not a POSIX function, and it means that every system
needs different defines to expose it. If the prototype of strsep
is not exposed then an ugly int/pointer is done and it might mean
a crash. The best solution?, to remove the strsep and make a custom
loop. If C programmers cannot do this kind of loops without calling
a library function, then maybe we should move all the suckless
software to Java.

config.mk

@@ -19,7 +19,7 @@ LIBS = -L/usr/lib -lc -L${X11LIB} -lm -lrt -lX11 -lutil -lXext -lXft \
        `pkg-config --libs freetype2`
 
 # flags
-CPPFLAGS = -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600
+CPPFLAGS = -DVERSION=\"${VERSION}\" -D_XOPEN_SOURCE=600
 CFLAGS += -g -std=c99 -pedantic -Wall -Wvariadic-macros -Os ${INCS} ${CPPFLAGS}
 LDFLAGS += -g ${LIBS}