changed e.protocol to e.short_label in admin/mzid_files
fixed some stuff related to use of short_label instead of protocol in admin controllers and views
added friendly_ids gem and made a test for mzid_files and s_i, doesnt work for the moment
friendly_id now works for mzid_file name and experiment short_label, migrations to add unique indexes, friendly finders in corresponding controllers
lots of changes and stuff
set stype to date in date column in index_exp_table in experiments index