Semi-automatically remove some trailing whitespace.
Implementation of multimedia editor.

This commit contains the changes by @qutorial and @bibstha that
implement a more sophisticated card editor, which includes the ability
to import photos and audio directly from the device.

This is squashed down version of a number of changes that were made,
with my own edits to remove changes that are not related to the feature
itself.
Merge pull request #40 from flerda/v2.1-multimedia-editor

Implementation of multimedia editor.
Bumped version to 2.1alpha4
Merge pull request #43 from hssm/indices

Add indices to new collections.
Cause Card.getQuestion to reload the note.
Calling Card.getQuestion with one argument is getQuestion(bool simple), which does not reload the card.
Calling it with just simple=true and then not using the return value seems pointless.
So use reload=true and simple=true.
(Also update the comment.)
Merge pull request #34 from ospalh/get-question-reload

Cause Card.getQuestion to reload the note.
Persist ints and force input type to integer in NumberRangePreference.

Since NumberRangePreference is only going to be used for ints, it
makes more sense to persist and retrieve values as ints only. Also,
don't make the input type configurable; it's always integers.
Implementation of collection preferences.