added first function to use RcppArmadillo
Revert "added first function to use RcppArmadillo"

This reverts commit 3b29d1de6fd636e8ad6aeb6012139a0851eb80fe.
Merge branch 'master' into Armadillo
switched almost completely to C++ utilizing RcppArmadillo
implemented the fast permudist in groupPCA and added support for rounds=0 in permudist just reporting distances between group averages.
defined header for angcalc.cpp properly
forgot to add header
removed adnormals.Rd and removed obsolete option mc.cores from docu in asymPermu
readded meanMat
forgot to export facenormals
added C++ version of Fortran code used by closemeshKD
finally switched completely to C++ routines.
added check for division by zero in angcalc.cpp