Help debugging malformed chemkin thermo files.

If, for example, your chemkin thermo file has a column of
spaces at the front, so your 1234 numbers appear in column
81 instead of 80, it is hard to spot without this help!
Better error messages for failing to read certain chemkin file problems.
Ignore SRI fall-off forms when trying to read chemkin files.

This is not yet implemented (see issue #131)
Allow certain types of ChemkinError to be ignored with a warning.

This allows you to just skip a reaction by doing:
    raise ("Skip reaction!")
Skip reactions with fractional stoichiometries in their products.

(Ranzi has a lot of these)
Better error handling when importing Chemkin thermo files.

Mostly helps you find the problems, rather than avoids them, but
does allow it to continue if there's a problem in a thermo entry
that is not actually used. (It does this by looking in the
speciesDict, so I'm not clear what happens if you don't have one)
Read (and use) default temperature ranges reading Chemkin Thermo files.

Syntax allows you to specify the defaults in the first line after the
THERM declaration. These are then used if not defined on each species.
Cope with silly formatting in thermo files, like "1.00D 04"

Some chemkin files out there have formatting like this, which
can't be parsed by a usual float()
Ammend diffModels to output the html file for model comparison.
First pass at sorting reactions.

Uses discrepancy function stored in the thermo
object.
Add functionality for sorting reactions.

May not be entirely accurate but is a good first
attempt at a sorting mechanism. It looks like
we will have to add additional functions for pressure
dependance in the kinetics model file.
Tidy up the comments added to the output thermo file.
Move import from within a function to the top.
Tweak chemkin thermo file reader.

Make it slightly more honest with regard the Chemkin specification,
and yet slightly more robust for files that break it!

We now read the fifth element/count specifier, if it exists.
Also in this commit, we TRUNCATE ALL SPECIES NAMES TO 18 CHARACTERS.
Fix bug in reading fifth element specification in chemkin thermo file.

It seems I was off by one in the column counting. Strange, as I thought
I had triple-checked it!
Parse more malformed chemkin thermo files.

Some people put random "0    " blocks in where there should
be element specifications.
Remove unnecessary debug code.
Fix and add robustness to mechanism comparing tool

allowing for removal of unidentified species from
species and reaction lists.
Remove reaction sorting by discrepancy, which is
currently not functioning.
Skip over pressure dependent kinetics when rendering.

Hopefully this will be fixed at a future date when
PDep reactions are supported.