Imported code into NetBeans. Cleaned up source code.

Removed a number of redundant statements. Removed usages of "this" by
properly renaming class-wide variables.
Wrote constructor tests.

First round of tests.
Made the Temperature class final.

The Temperature class is now final and its conversion methods are now
private. The API exposed by the class makes more sense this way: create
instance with value/unit pair, optionally set value, change unit and get
value.
Wrote normal case conversion tests.

Also modified existing tests to use JUnit's built-in double equality
assertions.
Wrote more normal case conversion tests.

Kelvin to X, Celsius to X and Fahrenheit to X.
Wrote tests for invalid cases. Renamed verification methods.

Added tests to check that exceptions are thrown when an instance of
Temperature is created with invalid values. Renamed some of the tests to
comply with Java's naming conventions (methods start with a lowercase
letter.)
Added documentation to the tests.
Added file headers and more comments.
Changed calls to assertTrue to assertEquals.
Wrote tests for the string representation.
Documentation fix.
Final commit.