Adding "Edit" button to entries

Added HTML for Edit button. Also started to add JS functions for entry editing, though they are not connected to the button yet.
Adding AJAX request to update_entry JS function

Changed 'edit' crud action and 'edit_entry' function name to use 'update' instead, staying consistent with existing update functionality.
Add functionality for "Edit" button

- Edit Entry form appears in place of entry text and is populated by existing entry.
- Added class to entry form textarea (will eventually replace id)
- Added entry content data to update_entry JS function (still not complete)
Converting spaces to tabs
Converting entry form IDs to classes
Changing jQuery tabs back to IDs to restore functionality
Moved edit entry form modifications into separate function
Changing click handler for form submit button

Submit button was not working on form elements created after page load (i.e. Edit Entry forms). Changed handler to accommodate this.
Changing JS update_entry to use correct textarea for submission
Enabling display of edited entries

Changed update_entry functionality to properly display the updated entry text. Since the entire entry is replaced by the form when Edit is clicked, the entire entry HTML needed to be replaced on submit.
Move the submit button to the left

So that we can put a cancel button on its right
Add a cancel button

In order to be able to re-show the content of the
post on cancel, the form now replaces only the
entry's contents, not the whole entry.
Don't give the user to edit rendered content

We render each entry – substitute shortcodes, YouTube
videos, add paragraphs, etc.

Currently, when we edit it, the rendered contents are
offered for edit. This is not very user-friendly, because
some of the substitutions are very unwieldily.

That's why we are now passing the original content, so
that we can give it to the user for editing.
Hide the Edit button when the edit form is active
Bring back the click event to the publish button

The publish button isn't in #liveblog-entries, but
in the outer div. It wasn't firing at all.
Bring back form tab label renaming

When updating, it needs to say Edit Entry, but we removed it by
accident in 71335a0.
Switch the jQuery mess in publisher to Backbone

In our case this fixes the problem with cloning the
insert/edit form. Having it as a view makes creating
and removing forms a breeze.

We still need to hook it with the Entry model, but
it's already more readable now.

Also, we still need to make the preview working,
since jQuery UI tabs work only with divs with IDs,
not classes.
Make the New Entry/Preview links act as tabs

When we click Preview the form is hidden and we
show the AJAX preview.

In order to achieve that we introduce a new view:
PreviewView, which is only responsible for the
Preview panel.