added an importer.py

for importing bookmarks n stuff

currently supports chromium bookmarks

usage:
in chromium: export your bookmarks to html file (bookmark manager)
./importer.py chromium bookmarks_10_11_14.html >> ~/.config/qutebrowser/quickmarks

** waiting for the perfectionist™ to judge me hard **
;-)
I'd write this using string formatting like this:

```bookmarks.append('{tag.string} {tag[href]}'.format(tag=tag))```

(untested)