Fix some bugs in the code for making a tentative match
added last week.
Add functionality for finding identical species in
previously added thermo libraries.
Try to fix unicode problems in reading "source" files.
Keep track of thermo matches and show in thermomatches.html view

As well as putting in the tentative matches list (although I am not sure 
about this really, as sometimes we match thermo of several conflicting
species) we now (also) store thermochemistry matches in a separate list
of thermo matches. There is a new web view to see this list and confirm them.

Currently there is no web link to clear an incorrect match from this list.

Also, when making matches, we now continue beyond the first matching hit, so
we can tell if it matches the same species from more than one library.
Look in sister directories for other (incomplete) thermo libraries.

In the end we should put all these in the database, but for now we tend
to have .thermo.py files lying around neighbouring directories of the model
we are importing, so we may as well use them.
Fix a bug in confirming thermo matches, but introduce another.

Don't have time to fix this one now, but it's closer than it was before,
and more obviously wrong.