Added new features to address issue #18.  The '/dynamic-' command line parameter can be used to disable dynamic in an entire set of files.  The [AllowDynamic] and [ForbidDynamic] attributes enable/disable dynamic support hierarchically on classes, methods, and packages.  [assembly:AllowDynamic(package=target)] is used to enable/disable dynamic on packages.
Fix for issue #220, AS and IS operators being compiled to dynamic code because of implicit conversion of Type to Class.
Merged from master