Start to unify the metric view

Due to many changes that have been made on this application I have to
apply these tedious changes to the metric view as well.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Encapsulate histogram to apply it on metric view

In order to display the histogram metric specific I have created a new
JavaScript file that is ought to encapsulate chart classes. Probably I
will move the score meter into this file, too.

This enabled me to add the histogram to the metric views, too. Now each
metric view displays the number of records, distributed by their score.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Track which and how often fields were completed

This statistic should give further insight into a repositories structure
with respect to their metadata records.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add treemap to visualize completeness statistic

I think a treemap is a suitable tool to visualize the completeness
statistic. Due to to its nested character it can probably visualize
the record structure, which is nested, too, very well.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Change analysis structure from flat to deep

Instead of a flat structure I will use a deep structure. This will make
the treemap input data generation a lot easier.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Transform completeness analysis to treemap input

The treemap is now served with the actual completeness analysis. I must
say this work very well, by switching between size and count it becomes
clear which fields are there, which fields are typically filled out and
which fields are not filled out.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add error page to avoid metric view exceptions

Before I start to make the whole missing data chain robust I will use
this error page. If there are no results it is simply rendered. Another
alternative could be the deactivation of the links on the snapshot view.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add custom view for the license metric

The license metric does not work very well with the generic view, hence
I have added this one. It is limited to show the number of different
licenses that are in use.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Integrate snapshot identifier into scheduling

The scheduling procedures were rather untouched from the whole snapshot
resource refactoring. I had to to make many changes, now the jobs should
be displaying the current status of a certain repositories' snapshot.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Escape dots from MongoDB field names

A horrible bug appeared when I wanted to save the analysis data from the
license metric. I took hours to find out that MongoDB prohibit dots in
the field names. Of course Mongoid and MongoDB, too, were failing
silently. The dot is now replaced, at least in the license metric, with
a rather ugly unicode version.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>