Add language analyzer

For the quantitative analysis of my thesis I am adding another analyzer.
For this language analyzer I found a gem which is in magnitude faster
and more accurate than whatlanguage.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Make small changes to models, views and controller

These are some of these commits which I cannot group under a reasonable
title. It includes small changes: updated indexes, formatting, updates
to the controller and updated views where I access the controller data
in a different way.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add repository index for the administration

I have added another repository index, but not for every user. This view
should be used in the future to delete repositories and snapshots from
the user interface directly.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add button to compile statistics for all snapshots

This commit is used for debugging reasons and for the quantitative
analysis I am currently writing. It is easier, than reimporting the
metadata all the time over and over again.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Fix statistics compilation to work with multiples

I had to introduce a series of fixes so the statistics compilation works
with more than just one type of statistic. Also, I added some logging
statements to make the progress more clear for me.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add button to compile just languages

Another button for debugging purposes. This time I want to be able to
just compile the language statistics, because the counting of number of
resources can be quite time and memory consuming.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Implement presentation of language analysis

The language results are now shown in the numbers tab as well. I had to
make many changes for this. I added a gem to retrieve the ISO-639 names
for each language. The table stylesheet rules display the table nicely
even when there is not enough space. Using em for the table cell widths
is a practice I should soon apply to all the other tables as well.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Update CKAN repository list

I have updated the CKAN repositories list. Since I drop the default
languages I have removed that field from the repository model class
as well. Also made some stylesheet changes for the language table.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add analysis to count create and update dates

This analysis is used to see when and how many metadata records were
created and when and how many metadata records were modified lately. I
am planning to visualize this data with a scatter plot.

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