Cleanup1008

This PR diff without whitespace changes: [?w=1](https://github.com/ReactiveX/RxJava/pull/1734/files?w=1)

A ton of style fixes:
- Removed spaces from empty lines and from end of code lines.
- Added spaces after some keywords and brackets.
- Changed tabs to 4 spaces.
- Added final modifiers to classes with just static methods and classes with private constructor.
- Removed final modifiers from methods in final classes.
- Modified casing of some local variables.
- Added missing headers to some java files.
- Added { } to if statements where missing.
- Removed unnecessary ```public``` and ```abstract``` and ```static``` modifiers from interfaces.
- Changed modifiers to be in correct order ```public static final ```.
- Removed unused imports and local variables.
- Removed unnecessary casts.
- Removed ```</dt>``` and ```</dd>``` tags from the javadoc of ```Observable``` as these tags don't need closing in javadoc.
- Added missing ```@Override``` and ```@SuppressWarnings``` annotations.
- Added more time to ```BlockingOperatorNextTest.testSingleSourceManyIterators``` as the original 10ms was unreliable.