added initial code for mutation landscape plot
added initial code for mutation landscape plot

From: Zach Skidmore <zskidmor@genome.wustl.edu>

git-svn-id: 274f1dac86931020afba6208eb04fedad756fa4a@113376 bc3139a8-67e5-0310-9ffc-ced21a209358

zskidmor/GenVisR,jkunisak/GenVisR,griffithlab/GGgenome,zlskidmore/GenVisR,zskidmor/GGgenome,griffithlab/GenVisR