[Evolution-hackers] Missing functions from libecal API reference doc

["Teresa Thomas" <tere ertw gmail com>]

After days of playing around with ESources and ESourceLists, I realized that all I needed was the e_cal_open_default() function from e-cal.h. Unfortunately, this function seems to be missing from the API docs. 

Please do add it to the docs, as it is quite a useful function. It is declared around line 204 of 
e-cal.h