Ignore vendor dirty git modules.
Merge pull request #356 from glogiotatidis/ignore-vendor-dirty

Ignore vendor dirty git modules.
[Fix bug 761559] Show multiple events ICAL export button
[Fix bug 761559] Initial implementation of URL handling query parameters
[Fix bug 761559] Add callback to icalendar button click
[Fix bug 761559] Initial object filtering for iCal population
[Fix bug 761559] Initial complete iCal export