Update fedorov.R

Added initialDesign function. Creates initial design for fedorov algorithm from candidate set by choosing points from the candidate set with the largest leverages
RcppArmadillo is also necessary.
Add initialDesign in C++

Makevars for linking to LAPACK for armadillo
Add R files for C++ code
Merge remote-tracking branch 'joncheryl/master'
Code style changes