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.
check that "parsed" lookup_hash is valid before using
Tighten validation regex for lookup hashes.
no longer need the Opteron/Linux constraints
by hand
's/model!=Opteron250 && type==LINUX64 && //'
s/select\[model!=Opteron250 && type==LINUX64\] //
s/select\[type==LINUX64\] //
s/type==LINUX64 && //
s/type==LINUX64 & //
s/ && type==LINUX64//
s/model != Opteron250 && //
s/ && model!=Opteron250//
s/model!=Opteron250// &&