calcurse-caldav: add HTTP support
calcurse-caldav: add HTTP support

Introduce support for HTTP connections. Use "HTTPS" in the config file
to enable/disable (default is enabled). The option modifies the prefix
of the host name to "http://" when disabled, rather than always using
"https://" with no option to change.

httplib2 automatically handles URLs beginning with either http or https.

Signed-off-by: Lukas Fleischer <c9ca73f8336dcfb037ec2c2abf52d80a6847a5cd@calcurse.org>

lfos/calcurse,lfos/calcurse,lfos/calcurse