The daemon must not adjust the "java.runtime.version" system property. This is not defined to be in System.getProperties() but is there in practice and setting it have unwanted side effects.
Added test to check that "java.runtime.version" is not copied from the host of the Tooling API.
Using Guava's ImmutableSet instead of Collections.unmodifiableSet.
Merge pull request #204 from kelemen/release

The "java.runtime.version" should not be updated by the daemon from the host of the Tooling API