Adding slug fields

Also changing old imports from defaultfilters to utils.text
Adding slug fields [adding migration files]

Also changing old imports from defaultfilters to utils.text
Adding fixture samples with slugs

Changing "Trimestre" to "Bimestre"
Minor changes
Changing context processor to pass class

It should pass class instead class_subject 'cause it should list
the class_subjects in another page
Changing Score from integer to fk

Then, we will be able to give students more then one score
Adding logic and lists to scores templates
Adding slug fields [adding migration files]

Also changing old imports from defaultfilters to utils.text
Adding Jquery and bootstrap min
Merge branch 'master' of github.com:TracyWebTech/xavier
Adding fix to schools

migration 0006 brakes if a str is given on slugify
Merge branch 'master' of github.com:TracyWebTech/xavier

Conflicts:
	fixtures/sample/2-periods.json
Merge branch 'master' of github.com:TracyWebTech/xavier
Adding .mo files
Merge branch 'master' of github.com:TracyWebTech/xavier
Merge branch 'master' of github.com:TracyWebTech/xavier
Merge branch 'master' of github.com:TracyWebTech/xavier
Adding get_current_subperiod method to periods
Removing period from periods sample fixture

Fixture had a period with another school
removing studentscores and changing fk to integerfield