added Sandbox and friends
refactored smooth-function implementations to use Sandbox instead of directly using FileList
added SandboxImpl.fileSystem()
refactored builtin smooth functions to use SandboxImpl instead of accessing FileSystem directly
fixed typo in message
redesigned plugin framework so @SmoothFunction are static and take Sandbox as first argument, parameters as second
added Problem.[equals()/hashCode()]
added reporting errors/warnings to sandbox
replaced calls to ProblemsListener.report() with calls to Sandbox.reportProblem()
redesigned plugins to report problems via Sandbox.report() instead of throwing exception
removed unused ReflexiveInvoker.invokeConstructor()
removed PluginInvokerFactory, made only method in ReflexiveInvoker static
merged ReflexiveInvoker into ReflexiveUtils
moved ReflexiveUtils to .utils package
refactored PluginTask/PluginInvoker