Fixed javadoc to be  compliant with Java 8's javadoc restrictions.

Added prominant TODO notices where I had to botch the javadoc where it may impact upon display.
Javadoc fixes for btchina.
Fixes for btce javadoc.
Fixed javadoc issues in campbx.
Javadoc fixes for MtGox.
Fixes to kraken javadoc.
Javadoc fixes to examples.
Merge pull request #184 from drdozer/feature/javadoc_8

Feature/javadoc 8