preparing for basic auth in managetask.php
implemented auth request
implemented login using given credentials. needs testing now.
added show_long parameter to getIcal method to allow showing tasks only on due date
added action "icalshort" for shortened task display in usual calendar software
added commentation
added hint for usage of icalshort to auth message
corrected redirect after http-basic-authenticiation
Merge pull request #26 from StephanRichter/ical-auth

Ical auth