fix #253
Add linkify function to qiita_pet.util
Improve study display pages

Provides links to pubmed for pubmed articles, and mailto links for users
(e.g., PIs of studies and users with whom a study is shared)

Fixes #199 by adding these columns to the dataTables on the studies pages
flake8 fix
Add function to convert params dict to JSON

With parameters sort_keys=True and separators=(',', ':')

Fixes #242
Use new params_dict_to_json function
Add suggestions from @antgonza and @teravest
Merge pull request #299 from antgonza/fix_253

fix #253
Merge pull request #300 from adamrp/issue-199

Issue 199
Merge pull request #301 from adamrp/issue-242

Add params_dict_to_json function