Whitespace.
Sanitize the chromosome name as needed for making a path
Quote the chromsome name for the shell
Print version we couldn't find instead of literal string.
Simplify shellcmd call--it always returns 1 or dies.
Remove redundant debug message.

shellcmd() already prints the cmd (as a status message) right before running it.
Check in advance for possible directory collisions.
Merge pull request #106 from tmooney/methratio_safe_chromosomes

Escape Chromosome Names in Methratio