compatible with openbsd

made the makefile compatible with openbsd, also since battery status is not exposed
trough the filesystem, just printing "not supported" for now.

makefile

@@ -1,6 +1,7 @@
-CFLAGS = -Wall -Werror -pedantic -Ofast -std=c99
+INCS = -I/usr/X11R6/include
+CFLAGS = -Wall -Werror -pedantic -Ofast -std=c99 ${INCS}
 LDFLAGS = -L/usr/X11R6/lib -lX11
-CC = gcc
+CC ?= gcc
 PREFIX = /usr/local
 MANPREFIX = ${PREFIX}/share/man
 

status.c

@@ -73,6 +73,7 @@ static const char * get_date (void)
 	return str;
 }
 
+#if defined( __linux__ )
 static const char * get_battery (void) {
 	static char str[ELEMENT_SIZE] = {0};
 	static int init = 1;
@@ -147,6 +148,11 @@ static const char * get_battery (void) {
 	}
 	return str;
 }
+#elif defined( __OpenBSD__ )
+static const char * get_battery (void) {
+    return "not supported";
+}
+#endif
 
 void die(const char *fmt, ...)
 {