quickmarks completion

It works, but:
* terrible performance (5s for ~1600 marks)
* split and join operations in the loop - i want direct access to name +
  url in the marks dict! how?
minor copy paste fails
der Sensemann
init quickmark completion in init_static
Improved qmarks model filling

thx to the fix from The-Compiler!
Merge remote-tracking branch 'florian/master' into quickmark-completion
updating code

according to https://github.com/The-Compiler/qutebrowser/pull/189#issuecomment-59220531
puschschsch
fixes
match urls with open, names with quickmark-load
selfish parameters
raising value error
Remove unused import.
Whitespace fixes.
Simplify getting of quickmarks
Fix long line
Fix indent
Merge branch 'quickmark-completion'