pascal p5c Code

assert.inc.pas
- use printf, so code for p5x & p5c is now common

clib.inc.pas
- system() now zeros last char in command string
this guarantees that string is null terminated, even when called with a constant string like

system('ls -l ');

note that this implies that there must be a trailing char att he end of the string to be zeroed

sys.inc.pas
- add NAME_MAX, the max nr bytes in a filename

gen
- pause if tp5c finds warnings in system environment

m-tests
- bug fix in mutate.pas
- code tidied up a little
- test.sh mods after testing on other systems

other minor code edits and comment additions & improvements