clean namespace and id, to remove internal zerolength whitespace characters etc that cause us problems
updated Priem.bib
copy biblio from aliases into item["biblio"] if no better source

should probably rename this file from webpage.py to generic.py or something like that
handle unicode in urls better, and copy in alias_dict_from_tuples

was unclear whether should copy this here to keep the providers isolated from item code, or use the one in item.py
once we move to a relational db this function+tuple/dics mixup will go away, thank goodness
update mendeley provider to supply aliases based on titles, and return mendeley urls etc.
accept dict as a alias type and call something with just biblio an article
Don't look up DOIs when importing from bibtex any more, just return the biblio.

DOI lookup done at alias state, so can use many providers (cross ref, mendeley, pubmed)
call webpage provider at end of that chain so that can at least supply provided biblio if no other ids
Merge branch 'master' into push_after_presentation
put biblio alias input in alias_tiids using json dumps
remove debugging printouts, whoops
try different order for webpage, now that we are storing the mendeley url
remove extra debug
updated piwowar.bib because was skipping some items on bibtex import
move lookup biblio by doi code into crossref from bibtex, integrate into crossref alias call