documenting share/contrib & a few test failures



(1) I've been writing texinfo user documentation for some
/share/contrib functions. Maybe we should have a standard way to tell
users that code in /share/contrib might change, might not be as well
tested as other code, ... Suggestions? A common link to an explanation
about /share/contrib?

(2) Also, minor bugs: with SBCL 1.0.22, rtest_gmama tests 313, 321, and 329
fail:

********************** Problem 313 ***************
Input:
relerror(gamma_incomplete(10.0 %i + 10.0, 10.0 %i + 10.0),
7.127479109547712499319385798936123b2 -
1.614519712336984904341104157868497b3
 %i, 6.e-15)

Result:
7.074835300932956162471479508475332b-15

This differed from the expected result:
true

********************** Problem 321 ***************
Input:
relerror(gamma_incomplete(2.5 %i + 10.0, 2.5 %i + 10.0),
9.830731859173691954817642978681044b4 -
6.937882767710646665454093742183442b4
 %i, 6.e-15)

Result:
6.480632530768504450390041867835266b-15

This differed from the expected result:
true

********************** Problem 329 ***************
Input:
relerror(gamma_incomplete(0.5 %i + 10, 0.5 %i + 10),
1.482285649085354026330085827685306b5 %i
 + 7.021741907380454401977225087894718b4, 5.e-15)

Result:
5.034250497105055506382144574477344b-15

Barton