Fastwiki support

[zioth]

To support drag&drop for the Fastwiki plugin's inline edit and inline section edit features, I did the following:

• Moved global initialization into an init function.
• Broke out all event handlers, so they could be turned off before being turned on. This prevents event leaks when the user goes in and out of edit mode. This is why the diff is so large; very little code actually changed.
• Called init every time fastwiki switched to edit mode.

[splitbrain]

LGTM

@annda can you please run this branch to make sure it still works as intended without fastwiki and also fix the travis config when merging?

[annda]

Works fine for me. Can't merge though, because of missing write permissions :-(

[splitbrain]

permissions fixed