Merge pull request #94 from cgruber/release

Merge release branch from 0.19 (for history)
Fix named() for array-types.  The simplified generics that were originally used (but weren't for, say, collections) caused the concrete type to be ignored and the abstract parent type returned from named().
Merge pull request #95 from cgruber/fixnamed

Fix named() for array-types.
Fix a bad bit of floating point math, and extract a utility class (with tests) for it.
Add one more assertion and a todo.
Merge pull request #96 from cgruber/fixmath

Fix a bad bit of floating point math, and extract a utility class (with tests) for it.
Bump version for 0.20 Release:

  * Bugfix to named() to support primitive array subjects properly.
  * Bugfix to float-comparing subjects where they handled float equality inappropriately.
Restore development versions.