Drop redundant try/catch exception handling

[Enchufa2]

There are two functions under src/utils.cpp that still add a second layer of try/catch for exception handling (on top of what BEGIN_RCPP/END_RCPP does). I'm referring to

rquantlib/src/utils.cpp

Lines 557 to 559 in 03f3efd

	} catch (std::exception& ex) {
	forward_exception_to_r(ex);
	}

and

rquantlib/src/utils.cpp

Lines 596 to 598 in 03f3efd

	} catch (std::exception& ex){
	forward_exception_to_r(ex);
	}

These try/catch blocks can be removed. The motivation is that I'm revising dependencies to try to phase out this old forward_exception_to_r function in the medium-term.

[eddelbuettel]

Should be very easy to replace that with Rcpp::stop().

[eddelbuettel]

I am removing the try/catch layer in those old helpers. No more forward_exception_to(ex).