Document new feature

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge branch 'master' of github.com:gammu/gammu
Fix indetation

Signed-off-by: Michal Čihař <michal@cihar.com>
Properly hangup with callid available

Signed-off-by: Michal Čihař <michal@cihar.com>
Whitespace cleanup

Signed-off-by: Michal Čihař <michal@cihar.com>