Started the implementation of shibboleth in mweb2, refs #376

Very first changes, migrating a bit of what was done in the master branch.
Not only copying the code, but improving it as much as possible.
Still a lot to be done, but already included tests for most of what was done
so far.

Had to add the migrations as done in master (using the same timestamps) so
the migration from the current master to branch-v2 will work (refs #987).
Implement a big part of associating a user with a shib account, refs #376

Not entirelly done yet, but the login, creation of ShibToken's, and creation
of a new user account are well under way, mostly finished.
Finish the basics of ShibbolethController and its views, refs #376

There's still a few TODOs in the code, but what is implemented in the master
branch was already migrated, the rest is improvement.
The views are working but some still need to be reviewed. There are references
to shibboleth throughout the application that need to be reviewed.
Version functional version of login via shib done, refs #376

Finished the last things that had to be done, specially in the views. There
are still TODOs in the code, but the login via shibboleth is already working.
These TODOs are improvements that can be done in the future.
Merge branch 'issue376' into branch-v2
More adjustments in news and join requests

Added tests and reviewed abilities, specially.
There's still things to be improved and a lot of tests to be added. Included
a few TODOs for some of these things.

refs #790
Fixed issue where all spaces are loaded together

Inside the index view page of spaces, all spaces are loaded together, this generate a overload who is transmitted to the user in form of slowness. Fixed this by adding pagination to this page, and was created a way to user find any space by searching by name or permalink. Some styles were changed to become padronized with the rest of site pages.
Merge branch 'branch-v2' of github.com:mconf/mconf-web into branch-v2
Merge branch 'branch-v2' of https://github.com/mconf/mconf-web into rnp-institution