Updated Compucell

Radiation
-Implemented radiation to kill a proportion of cells at a specific
monte carlo step
-Used data from U87 cell line for survival probabilities

Dedifferentiatoin
- Dedifferentiation is applied after radiation is applied
-After each dose of radiation, a non stem cell has a certain
probability to dedifferentiate into a stem cell with increasing an
increasing probability with each additional dose

Plots
-Modified python code to plot total volume of each cell type rather
than total cell population to better represent the proportion of dead
cells in the simulation since dead cells don’t actually get removed

Bug fixes
-corrected an error in which non stem cells were able to divide, now
only stem cells are able to divide whereas non stem cells are only able
to die or dedifferentiate
-Divided the parent cell target volume by 2 after division