[PATCH] Fixes to parse_options, help info from display

[Bill Spitzak]

These are a series of changes, you can pick and choose from them if you don't like them all.

There are fixes to the parser so that "x=5mm" and "bool=false" and other constucts are errors
rather than doing unintuitive things.

Also I tried to get most of the weston demo programs to print some help if -h is given or
if there is an error in the command line. The eventdemo one in particular, since the web
page for building claims --help will give you some help. Note this is just done quickly
without extensive rewrite, so in most cases it does not distinguish -h from errors and
returns an error code in both cases. I don't think it is necessary to complicate the
demo programs more than this.