Merge pull request #11 from pippijn/master

LAN discovery test + no-rtti and no-exceptions
Javadoc fixes and CMake javadoc building

Fix some issues with the javadoc (missing periods after sentence etc).
Passing -DBUILD_JAVADOC=ON to CMake will result in the javadoc being built after compilation of the java code.
Fix javadoc for validatePublicKey
Implement assert() for tox4j

This assert function checks the condition, and if the condition is
false, immediately aborts with a FATAL ERROR and a java stacktrace.
Update README.md
Update README.md
Implement tox_save
No need to allocate heap strings in tox4j_assert calls.