analyse_commits.pl: Fix Excel usage

Suppress " " quotes around E-mail addresses to prevent Excel
from mis-interprerting them as the end of the cell.

Also fix the detection of merge commits which was broken by add
"" quoted into the empty list of filenames that Excel needed to
form cell content.

Note that the .cvs file needs to be renames to .xls for Excel to
properly show the contents.

Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>