cubature

Updated this package in several ways:

• Now using Rcpp (as of version 1.2)
• Synced up to newer version of cubature library (version 1.0.2) by Steven Johnson so that both hcubature pcubature are now available.
• Added vectorized interface to hcubature and pcubature
• Added a vignette to show the great gains from vectorization
• Added tests to avoid screw-ups
• Fixed up clencurt.h so that CRAN size limitations are not violated