-Created some new kids of search, including the featured search
-Created an empty admin page
Merge branch 'master' into featured

Conflicts:
	MokapBackend/src/main/java/es/eucm/mokap/backend/model/search/SearchParamsFactory.java
-Adapted some fields not currently recognised by RepoElementFields, we'll rewrite them when the RepoElementFields class gets updated in repository
Merge remote-tracking branch 'upstream/master' into featured
Created jsp pages and a controller to handle the featured administration
Created an enum to manage the different categories of featured elements

Modified the jsp files, another step towards the good direction
Added functionalities:
-List the current featured elements (index.jsp)
-Add a new featured element (index.jsp)
-Featured search with the parameter f (Need to use SearchRequestFields to make it prettier)
-Better managing of index documents

Some changes to other classes to make this work:
-Added new error strings
-Some other minor changes
Minor fixes, pending:
-Actually check if the user is allowed
-Functionality to remove featured content
-The usual Jdoc / exception handling stuff
Added featured removal functionality
Now we actually check if the logged user is whitelisted
Featured working:
-Added a method that checks if the category can be used to add elements

Unrelated: Added repositories to pom.xml
Merge pull request #38 from mdebenito/featured

Featured elements patch