Error in TeX symbols in displayed plot

[Michael D Godfrey]

I tried replacing all /Symbol by /Symbol=10 in the function
__setup_sym_table__ in __go_draw_axes__.m

Tests of text with and without  exponentiation indicate that this change
works.

I am still not confident that there are not other negative side
effects.

If someone who is familiar with this code says it is OK, I will
submit a changeset for __go_draw_axes__.m


Michael