Updated the JSON export to include all skeleton metadata
Added treenode_connector creation time
Added API to retrieve creation times of connector-associated links
Review API with review_time included
Clustering Wizzard: Order ontologies and graphs by name

This orders the ontologies (step 1) and classification
graphs (step 2) in the clustering wizzard by name.
Add comment (TextField) to Project model
Migration: add comment field to Project
Make comment field searchable in admin

The 'comment' fields of Project and Stack can now be searched in admin.
Merge pull request #708 from fzadow/clustering_order_ontologies_and_classifications_by_name

Clustering Wizzard: Order ontologies and graphs by name
Merge pull request #709 from fzadow/add-comment-field-to-project-model

Add comment field to project model
WIP
Making compact-json fast again by creating a new URL compact-skeleton.

Includes dynamic loading of reviews in the WebGLApplication,
which means that for the common case (coloring skeletons by source)
the reviews are not loaded, therefore increasing query and transfer speed
while also reducing memory demands on both client and server.

Necessitated of a generalized fetchSkeletons recursive ajax function
to avoid duplicating functionality, by adapting and renaming the old
fetchCompactSkeletons function from utils.js.
Arbor.js: fix indentation in a couple of functions.
Arbor.js: Gaussian convolution of slabs to compute smooth cable length
and also to smooth the position of skeleton nodes.
WebGLApplication: add option to smooth skeletons with a Gaussian convolution.

It is surprisingly fast and looks great, removing all jitter.

Could be made even faster by caching distance measurements.
WebGLApplication: refresh skeletons when toggling Gaussian smoothing.
Merge branch 'master' into morphology-pca

Conflicts:
	django/applications/catmaid/static/libs/catmaid/Arbor.js
Arbor.js: save two ops (one sqrt and one squaring) for every estimation of Gaussian weight,
increasing performance as always: by doing less.
Arbor.js: new function resampleSlabs

Leaves all root/branch/end nodes in place, and resamples the nodes
in the slabs to a desired node interdistance.

The last edge of each slab (prior to reaching a branch node or an end node)
will be equal or shorter than the desired node interdistance.

The resampling is based on a Gaussian convolution.