Header fixes:

* Do not include system headers in shared files (stdlib.h).
* Don't include lcd.h only once in each driver.
* Remove some unnecessary headers from driver (e.g. syslog.h)
* Include <poll.h> instead of <sys/poll.h>
* Spelling fixes.

server/drivers/hd44780-serial.c

@@ -50,6 +50,8 @@
 #include <termios.h>
 #include <errno.h>
 
+#include "lcd.h"
+#include "hd44780-low.h"
 #include "hd44780-serial.h"
 #include "report.h"
 
@@ -81,8 +83,8 @@ unsigned int bitrate_conversion[][2] = {
 #endif
 #if defined(B230400)
 	, { 230400, B230400 }
-#endif	
-#if defined(B460800)	
+#endif
+#if defined(B460800)
 	, { 460800, B460800 }
 #endif
 #if defined(B500000)