Added unit tests showing that GC'ed SoftReferences are not cleanup from memoize caches
Fixed cache's SoftReferences instantiation in order to register them in a ReferenceQueue
    GROOVY-5802
GROOVY-5802: tweak test
Fix for GROOVY-6042: Do not assume that keys are strings
Merge pull request #140 from paulk-asert/groovy5802

GROOVY-5802: Exception thrown in groovyConsole
Groovy 6041: Generics in signature causes abstract class error
GROOVY-6042: Removed two explicit casts that may fail at runtime
GROOVY-6047: NPE in type checker using an extension
GROOVY-6050: Fixed inconvertible types error
GROOVY-6043: Precompiled type checking extension scripts support
GROOVY-6045: Safe call flag should be ignored if object expression is "super"
GROOVY-6051: Fix NPE in generics return type inference
Fixed ListHashMap (remove not really supported)
GROOVY-6035: Regression in closure return type inference
GROOVY-6058: JsonSlurper should support URL and File variants for parse
Merge pull request #147 from paulk-asert/json

GROOVY-6058: JsonSlurper should support URL and File variants for parse
GROOVY-6053: Try iterating or transforming Object into Collection in DefaultGroovyMethods like count(), sort() and other Collection methods.
Merge pull request #148 from paulk-asert/groovy6053

GROOVY-6053: Try iterating or transforming Object into Collection in Def...
GROOVY-6053: Try iterating or transforming Object into Collection in DefaultGroovyMethods like count(), sort() and other Collection methods. (minor refactor)