Fix missing overview dots for dynamic analysis

This commit fixes a bug where no dots appear on the dynamic
analysis plots when there are zero defects for a given day.
Also make sure the number of defects is shown

Similar to the previous commit, report 0 defects as opposed to
blank.
sanitize more problematic chars for javascript

Add open paran and close paran to the list of characters that
break our javascript processing.
Merge pull request #2 from Kitware/fix_overview_DA

Fix missing overview dots for dynamic analysis