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.c

@@ -73,7 +73,6 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
-#include <fcntl.h>
 #include <string.h>
 #include <strings.h>
 #include <errno.h>
@@ -699,7 +698,7 @@ HD44780_flush(Driver *drvthis)
 	}
 	debug(RPT_DEBUG, "HD44780: flushed %d chars", count);
 
-	/* Check which defineable chars we need to update */
+	/* Check which definable chars we need to update */
 	count = 0;
 	for (i = 0; i < NUM_CCs; i++) {
 		if (!p->cc[i].clean) {