[ADD] sms: sms gateway using iap

addons/calendar_sms/__init__.py

addons/calendar_sms/__manifest__.py

addons/calendar_sms/i18n/calendar_sms.pot

addons/calendar_sms/models/__init__.py

addons/calendar_sms/models/calendar.py

addons/calendar_sms/views/calendar_views.xml

addons/sms/__init__.py

addons/sms/__manifest__.py

addons/sms/models/__init__.py

addons/sms/models/mail_thread.py

addons/sms/models/res_partner.py

addons/sms/models/sms_api.py

addons/sms/views/res_partner_views.xml

addons/sms/wizard/__init__.py

addons/sms/wizard/send_sms.py

addons/sms/wizard/send_sms_views.xml