* 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.
- explicitely declare void arguments
- make a few string args const
* better support for shorter displays in server screen
* make target to create top level tag file
* support display heights > 4 (treated like height = 4);
* determine number of user-defineable chars using get_free_chars();
* allow custom chars starting at a character position (offset) != 0
* update and extend documentation
mmdolze