MPFR Support.
New distributions: laplace, logistic and hypergeometric.
Added PCH support to the Jamfiles for faster build times.
Added C# usage example.
Updated and regenerated docs.
Also fixes#2799 and updates the tests to catch this failure in future.
[SVN r51455]
Previous fix was incomplete, so added new tests, confirmed problem report, and added fixes.
All the tests now compile cleanly with g++ -pedantic -Wall -Wno-long-long (checked with gcc-4.4.1 and 3.4.4).
[SVN r42012]
