global exception handler that is used in battery instead of tryCatch

Usage

withExceptions(expr, error = NULL, finally = NULL, meta = NULL, session = NULL)

expr: - any expression
error: - function that will be triggered on error default NULL if added it should return add add meta data create.error(cond, list(...)) it is used internally by battery, it can safely ignored.
finally: - function that is always executed when the expression is done, no matter if it raised an error, signalled an exception or finished normally (it is always invoked exactly once)
meta: - context of the expression (origin, type, ...) passed to the handlers
session: - optional shiny session to create exception handler only for given session