[jsapp] use offsets for view column buttons
[jsapp] make pagecolumn buttons span4
[jsapp] set input size on pagecol inputs
[jsapp] page-column mobile fixes

 * Remove class="form-horizontal" from column-canvas, it was a waste of space.

 * Move action buttons inside column-canvas, and put a dividing line at
   the top.

 * Add class="clearfix" to widget list, so it expands vertically
   correctly.

 * Fix spacing on action buttons so there's less overlap
Merge branch 'mobile_fixups'