ggcorr option: print correlation coefficients
ggnet option: support layout.par

this allows to pass complex graphing parameters (see sna::gplot.layout)
ggnet: labels at mid-edges
tiny example improvement
bugfix

remove useless warning
support for geographic networks
geographic coordinates, custom weights from network attributes
better geo option
bug
added ..Rcheck to .gitignore
added corMethod to ggally_cor
all cor fns are now cor_fn to use same parameters
added na.rm to all min/max/range commands
only remove rows if corUse is 'complete.obs'. Set default corUse to 'complete.obs'
added parameter matching and more cases for the removing warning
fixed corUse being an integer and not a value
changed the ddply command to not rely on eval within ggally_cor
make the cordf labels have the correct level order
added ..Rcheck
white space