Updated generic_mode to use additive stepping where appropriate.
Improved NC-Beta PDF calculation and termination conditions.
More or less got non-central T finished off: quantiles now work, PDF and mode almost correct.
Fixed typo in toms748_solve.hpp
Updated NC-T tests to include mode and quantile.
[SVN r43333]
Added extra common error handler.
Factored out some generic quantile code.
Killed some warnings in NC Beta.
Added initial non central T.
Fixed a few doc typos.
Added initial NC T tests.
[SVN r43324]