There is a small bug with parallel when using a perforce repository,
actually this seem to be broken for any repo.
When doing a parallel view codestriker will pull the current version of
the file from perforce and placing each line of the file into an array.
When codestriker is displaying the common parts of the file when doing
a side by side diff it was using the run line number of the previous
version of the file.
Since the line numbers and the actual lines in the array do not
correspond now this resulted in missing lines.
Also added a check to make sure there are actual lines in the file array
since a failed p4 print would result in an empty array and then a side
by side diff with a bunch of blank lines.