Report undeclared reference names
Install a GWT on vtable dispatches

This fixes a bug where the guardWithTest was created but overwritten by the vtable dispatch method
handle. This could have caused wrong dispatches on megamorphic call sites with dynamic and
non-dynamic objects.
Give a fairer shot for Groovy on surrounding loops
Introducing an invocation token
Introducing the orIfNull operator

The usage is best illustrated with an example:

    let map = java.util.HashMap()
    println(map: get("bogus") orIfNull "n/a")

would print "n/a".
Documentation for orIfNull
Experimentations with an elvis operator

This could allow null-safe method invocations, like:

    person: address()?: city()

Calls with ?: instead of : return null if ever done on a null reference:

    null?: plop()

returns null, while:

    null: plop()

throws a NullPointerException.
Clarifying legal and technical considerations
Elvis tests refactorings
Documentation for null-safe method invocations
An example of dealing with null-safety
Tolerate the lack of a newline if the last line is a comment
Trim code block delimiters to 4 characters
A note on newlines
Forgot the license header
Back to Travis-CI default email notifications
Merge pull request #9 from jponge/wip-elvis

null-safe method invocations
Version 0-preview2
Upgrade to 0-preview3-SNAPSHOT