Disable default syntax table

This change disables the default syntax table, this will prevent
multiline string matches.  Using the default syntax table causes
syntax highlighting errors when some log lines contain unmatched quote
characters.  It also changes the fontlock so that it will match case
insensitively which simplifies some of the fontlock keyword matches.

It also disables undo in the buffer.

Sorry about the tangled changes, it probably should be 3 commits.  I
can split them up if required.

Cheers,
Russell