Minor cosmetic changes.
Webserver: minor wording changes to the 404.html file.
Webserver: update web/default.css.

* Add normalize.css minified with `cleancss --s1 -b`
* Add box-sizing
* Remove float with display:inline
web/javascript.js: Fix a few JSHint warnings.
Update coverity.bat.

* the COVDIR variable can be set to specify the coverity dir
* use our build.bat as the coverity build command
* build release filters too
Fix size specifier in Format().
Fix uninitialized class members.

Found by coverity.

Again...
build.bat: Do clean instead of rebuild when using /LAVFilters switch. It will be build anyway.
Use Microsoft's froward links in Compilation.txt.
web/javascript.js: Fix more JSHint warnings.
Improve the Get(Cur)DispMode and SetDispMode functions.

Fixes CID #966222.
Ensure the correct thing is casted.

Fixes CID #965944.