rename BrowserQuitException to JumpToTopLevelException for more general use
refactor quit to separate cleanup action and implement GNU R semantics more closely

Cdqrls is implemented as R function, which invokes .fastr.dqrls,
which is invokes Fortran routine dqrls through RFFI.

The new pretty-printer skeleton implementation integrated with the FastR. It supports the following data types: named and unnamed vectors, matrices, String and Double.

compile graphics/grDevices C code directly from GnuR; build fficall/common independent from fficall/jni