Improve documentation

- Simplify language in documentation
- Update URL of "Code Conventions for the Java Programming Language"
- Use CLA=0x00 instead of 0x01
- javadoc: Remove empty "p" tags
- javadoc: Add "." to first sentence
- javadoc: Fix errors detected by Java 8's javadoc
Merge pull request #59 from robertbachmann/doc

Improve documentation