Problem when inserting new lines that run off the bottom of the page - 
bounds checker flags error.

Problems with inserting blank lines into documents.

Retransmission protocol still incomplete - if last person to make a
change leaves a conference, no retransmissions happen until someone
else changes something.  (code not yet written).
- New timeout feature, waits 10 seconds for a sliding key message of
        some sort (either sending or receiving). If we haven't seen
        one after that period, we have a random wait (to avoid
        collisions) of 5+/-3 seconds before attempting to start our own
        cycle. 

Prolonged network partitions may not resolve themselves immediately
(code not yet written).
- Checksum protocol. Current site now sends out a page checksum when all
        retransmissions have died down to their lowest levels (trying to
        rely on the existing protocols first). Other sites can compare
        checksums for their page and, if they don't match, for their
        blocks.

Dynamic block length calculation is not always correct - sometimes
stars reoprting lost lines appear at the end of complete blocks, or
the last line of a block gets duplicated.
- Possibly due to lines with the same time being received one after
        the other. The second line was being ignored. Fixed so that
        we now accept lines
- Block calculation is now localised, the local site keeps track of
        the number of lines in their block. Fix also in place for
        delete line so that the number of lines in a block can never go
        below 0. As the block no_of_lines variable is unsigned, -1 is
        stored as 65355, when display_block is called it trys to add
        65355 lines of '**' to the block to signify missing lines.

Multiple nt's running one one machine do not perform correctly (not
sure if this is a feature or a bug :-)

Odd things happen when multiple mouse buttons are held down
simultaneously.


