WEB and COMPARISON: CITATIONS and REFERENCES

[martin-henz]

I would be nice to make citations clickable. For that we would need to do the following.

In the text:

<CITATION>Henderson 1980</CITATION>

becomes

<CITATION NAME="HEN80">Henderson 1980</CITATION>

and in 97references97.xml,

<REFERENCE>Henderson, Peter. 1980.  <em>Functional Programming: Application and
      Implementation.</em> Englewood Cliffs, N.J.: Prentice-Hall.</REFERENCE>

becomes

<REFERENCE NAME="HEN80">Henderson, Peter. 1980.  <em>Functional Programming: Application and
      Implementation.</em> Englewood Cliffs, N.J.: Prentice-Hall.</REFERENCE>

Then we can generate appropriate links in WEB and COMPARISON

[martin-henz]

Needed for https://github.com/source-academy/sicp/issues/99

[martin-henz]

I suggest we work on the rendering of citations and references, first, to match the original textbook. The linking for the web edition should have lower priority (after book manuscript deadline).

[martin-henz]

I don't see this happening any time soon.