added slidify lecture
Fix paths to images; add html/md files
Roger's Reorg
Merge remote-tracking branch 'jtleek/master'
rogers reorg
added slidify lecture
Merge pull request #25 from seankross/master

added slidify lecture
Merge remote-tracking branch 'jeff/master'

* jeff/master:
  added slidify lecture
  rogers reorg
  added slidify lecture
Merge remote-tracking branch 'origin/master'

* origin/master:
  added slidify lecture
  rogers reorg
  added slidify lecture
Merge remote-tracking branch 'github/master'

* github/master:
Lecture on R Profiling
Edit paths
Merge pull request #26 from rdpeng/profiler

Profiler
Merge branch 'profiler'

* profiler:
  Edit paths
Move plotting lectures into EDA
Lecture on principles of data graphics
Plotting systems in R
Merge pull request #27 from rdpeng/plotting

Plotting
Rename plotting directory
Updated base plotting lecture
Separate lecture on Graphics Devices