Encode all &, <, and > in markdown.

This is non-standard markdown!  But it has the advantage of creating valid HTML more often, so I think on balance it's a win?

This means that this translator will *not* translate valid HTML in markdown to actual HTML.  I figured this was a more uncommon occurrence than (say) all the biomodels notes that have "<=>" as a reaction symbol, or that have '&' in a URL.

We can drop this (I think) if tim-gromeyer/html2md#158 is addressed.  But Maddy might need updating as well.

Anyway: hack for now, but happy to revert if people think the cost is too severe.

 update news

Added MATLAB binding for the new FBC variables

bump version

Merge pull request #304 from sbmlteam/docs

Docs

Merge pull request #270 from sbmlteam/bump-version

 - bump to 5.19.7

Merge pull request #243 from sbmlteam/fbc-v3-fix

 #241:issues with fbc v3

dont use ninja on manylinyx

Merge pull request #189 from giordano/mg/fbcspeciesplugin-c-api

Fix signature of prototypes of `FbcSpeciesPlugin`

Merge pull request #99 from sbmlteam/fix_spatial_batch

- missing cpp files in common