adapted add method in class.timetracker.php to accept end date
altered managetimetracker.php to read ttendday
added second date field, needs to be adapted
added language strings for date fields
renamed 2nd instance of calendar to theCal2
fixed some ids. The second field is functional by now. Not included in themes other than standard, no translation for languages other then en and de up to now.
modified managetimetracker to accept separate end date, modified respective form to offe a second calendar
added second time field for editing timetrack entries. only included in standard theme.
Merge pull request #28 from StephanRichter/cross-midnight

Zeiterfassung über Tagesgrenze hinaus