1) ` vars which are always expanded.
2) & vars which are expanded "sometimes" (generally for display stuff).
3) "pure" vars which are only expanded when they are the entire string.

The main change here is in the & var handling... lw() no longer
expands these, so they can be displayed to the user... they are now
expanded in the following cases:

1) Anything that calculates the displayed length.  The assumption
   here is that the string will be passed to one of the following
   things.
2) Bar updates, either @quebar or @saybar
3) @do addlog
4) @do write
5) @moremap
6) @progname
7) @show
8) @writefile

I think I was intending to strip & and prevent those variables,
but it looks like the original doesn't.

However, it also looks like the original doesn't *always* replace
string variables... will need to look into that harder in the future.

As of this commit, LORD2 keeps track of the last time a key was
pressed, and a timeout occurs five minutes after that if it's
waiting for a key.  This has issues as the getstr() timeout does
not behave in this manner.

However, if the timeout callback style works, getstr() and the other
dk functions can grow callback support pretty easily, and this seems
like it may be the best way forward.

Further, disconnect handling should be tied up in this, and dorkit
does not have very robust features for this.  In most cases, a
disconnect will be treated the same as a timeout, so the same solution
should likely be usable by both.

The biggest challenge is preventing the need for all the code to
have exceptional condition handling, which can be quite tricky as
battles can end by running a REF file (For example, the training
centre).  This would mean all code paths reachable via REF calls
would need to fail nicely in the face of a connection loss/timeout.

About the only thing still missing is the ALLOFF utility which is
simple enough, but various other bits really need to be fixed before
that is done.

Beginnings of the map editor created, common functions from lord2.js
moved into l2lib.js for sharing.