Add Pip update note to installation instructions
Classification: fix wrong url tags in graph display template

These definitions were wrong due to a deprecated feature in Django
1.5. All url tags that refer to a named url are now required to be
quoted. Otherwise, they are interpreted as a context variable.
Remove some unneeded template imports

These imports became unneeded due to a deprecated feature of Django 1.5.
The imported functionality ("new style" url tags) are now the default.
Fix broken display of custom admin views

The parameter order changed in the function we use for registering
custom views with admin plus. Since we updated django-adminplus, which
we use for the custom views, along the Django 1.6 update, we were
affected by this change. This commit fixes the registering of our custom
views to conform to the new signature.
Fix more url tags in different Django templates

These definitions were wrong due to a deprecated feature in Django
1.5. All url tags that refer to a named url are now required to be
quoted. Otherwise, they are interpreted as a context variable.

The templates fixed by this commit should be the last ones.
Style change: make catmaid.admin module more PEP8 complient
Let isreciprocal field of Relation model default to false

Since Django 1.6 a BooleanField defaults to None instead of False, if a
default value isn't specified. Therefore, this commit adds a default
value to this field to maintain current functionality and to be more
explicit. The isreciprocal field of the Relation model was the only
BooleanField without a default value. This is fixed now.
Tracing statistics: use correct labels in legend of pie charts

The legend showed the wrong labels/names since commit 53a94ce. In the manual
legend drawing routine, I expected the names to be ordered according to the value
object. This is not true. The pie chart values are an object, after all---so no
specific order should be assumed. This commit fixes this by using the correct
indicates for the name list. These are available from each value entry.

This fixes point 5 of issue #625.
Tracing statistics: separate status view handlers from actual processing

Doing this makes debugging and performance optimization way easier.
Tracing statistics: improve code formatting in back-end
Tracing statistics: remove not used inputs and relation map
Tracing statistics: make all imports explicit

Using *-style imports puts a lot of things into the module's namespace,
potentially shadowing things from earlier imports. Avoiding them makes
the code more readable and robust, because you exactly know what is
imported. In theory, it also saves a tiny bit of memory and reduces
loading time. Additionally, I can use pyflakes to look over the code.
Tracing statistics: improve performance of user node count

Joining the treenode and the user table is costly. Therefore, this
commit decomposes this into doing the count/aggregation first and then
getting the names to the user IDs in a fast second query.

In my test data set with 6677982 tree nodes this improves the
performance of this query from 2.4s to 1.5s.

This commit is part of dealing with issue #625.
Tracing statistics: improve performance of review editor queries

Like with the node creation query, it is much faster if one gets the user
information separately. For the 6677982 tree node test set, the review stats
timing went down from 2.4s to 1.6s and from 950ms to 890ms.

To improve performance further, it might be sensible to omit the user name
query on the back-end and use the user information stored at the front-end to
replace the user IDs.

This commit is part of the work for issue #625.
Tracing statistics: bring node count API more in line with rest

Instead of using /stats one now can get the node count with
/stats-nodecount. The basic query itself is now done with raw SQL as
well. This, of course, doesn't bring any performance benefits, because
it is the very same as what the Django ORM created.

This is related to issue #625.
Tracing statistics: make URLs more REST like

This is only a cosmetic change. Instead of e.g. /stats-nodecount there
is now /stats/nodecount in use. This adds more consistency with the all
the other URLs.
Tracing statistics: simplify widget initialization

There is no dedicated view class needed for the statistics widget. A very simple
template is returned. Therefore, this commit employs Django's built-in
TemplateView directly. The URL to retrieve this widget has been simplified as
well: instead of /statisticswidget is now reachable with /stats.
Tracing statistics: split page refresh in sub methods

This improves in my eyes the readability of the code.
Tracing statistics: ensure statistics are loaded after layout

This commit moves the request of the actual statistics in the callback of the
layout loading, because we can't know how long it takes for the layout to be
available.
Tracing statistics: make user history date range adjustable

This commit adds two new text boxes two specify a start and an end day
to show the user history for. It can be adjusted with the help of a new
"refresh" button next to it. The start defaults to ten days ago.

This is part of the work for issue #625