plot_pca_projection: Plot PCA projection and data points from original PCA
In KSheu/ksheu.lib: KSheu Library1

Plots projection from rotated.scores file (output of intersect_do_PCA_and_project_second_dataset) on top of original data

plot_pca_projection(file, rotated.file, info.name, info.type, info.name2,
  info.type2, title = "Projection", labels = F, PCx = "PC1",
  PCy = "PC2", ellipse = F, conf = 0.95, fliph = F, flipv = F,
  save = F, savename = "")

`file`	scores file of original data
`rotated.file`	File containing scores matrix of projected data
`info.name`	Vector of sample names in original PCA
`info.type`	Vector of sample types in original PCA in the same order as names
`info.name2`	Vector of sample names of projected data
`info.type2`	Vector of sample types of projected data in the same order
`title`	Title of the plot
`labels`	default=T
`PCx, PCy`	PCs to display
`ellipse`	Construct confidence region based on groups in info.type, default = T
`conf`	default = 0.95
`fliph, flipv`	flip plot hoirzontally or vertically
`save`	save plot as png
`savename`	name of file saved