began writing problem statements for hw1 questions from fox.
updated preamble.
changed to ignore .Rnw build output.
fixed white space and typos.
Added problem statement for #6.
starting working on EDA.
replaced ggpairs code with native stats::pairs().
started implementing data.table approach to plotting columns.
updated prob6a work to involve manual density/histogram and boxplot creation.
started adding commentary on EDA visualizations.
added more commentary on problem 6.a.
added solution to exercise 5.3.
added solution to #5.
Added solution to problem #4.
added solution to problem #1.
added problem statement for #2.
added solution to problem #2.
fixed some typos in around problem #1.
merged in master to update .gitignore.

Merge branch 'master' into hw1

Conflicts:
	.gitignore
added .Rproj file.