[dev] [surf] patch for pseudo-uri idioms

Hi folks

I added some logic to surf's uri loading to make it handle a few useful
idioms not understood by webkit:
* Loading a blank uri goes to homepage instead of nowhere. This works
any
    time, unlike the existing homepage patch that only does it on
invokation.
    So now, ctrl-G, shift-enter takes me to my search engine
(duckduckgo).
* `javascript:alert('hello');` works as expected in other browsers.
    Kind of useful sometimes.
* loading valid filenames will load the file even without file://.

I find that these (especially the homepage thing) really improve my surf

experience.

I also put the spacial nav option with the other ones like it
(loadimage,
plugin, script). I don't use it (spacenav), but I left it on (surf's
default) for the patch.

To use it, you need to apply and then add

    static char *homepage = "<your homepage here>";

to your config.h.

I'll put it on the wiki as-is unless there is anything you guys can
think up
to improve.

Happy hacking!

/wolf