probsoln package versions:

Version 3.05:

  * Now allows comma-separated list of file names in
    \loadrandomproblems and \loadrandomexcept

Version 3.04:

  * fixed bug in textenum

version 3.03:

  * added facility to exclude problems selected in the past n years

version 3.02:

  * Added xkeyval to required package list

  * defproblem, onlyproblem and onlysolutions may now contain
    verbatim if fragile option set

version 3.01:

  * Problems may now contain floats in their definition

  * Problems with arguments may now specify a default argument
    to be used with \foreachproblem and new package option
    "usedefaultargs"

  * Added \foreachsolution

  * Fixed bug in random number generator when n = 7. (Use
    \PSNuseoldrandom to ensure compatibility with older versions.)

  * \loadrandomproblems generates a warning instead of an error
    when more problems are requested than the maximum number

  * Added \loadexceptproblems and \loadrandomexcept

  * substr package no longer required

Version 3.0: Rewrote package to use data sets to make it easy
to reuse problems so that the solutions can be placed in 
a different section of the document to the questions.

Version 2.04: fixed license text

Version 2.03: Added starred form of \newproblem for problems without
solutions. Checks to see if solution environment is already defined.

Version 2.02: Added \selectallproblems which selects all the problems
in a given database, in the order in which they were defined.

Version 2.01: Provided means to customise the way in which randomly
selected problems are displayed. Added \doforrandN command (like \@for
but for a random subset of the specified list.) Added \random command
which stores a random number in the given range in the specified 
counter.
