Remove  duplicated code ( toSDMM )
Change Send Mail logic for Unix plateform (#FS 1096 )

The default method is now with xdg-email via the local mail service .
Nevertheless, the possibility to send mail directly via SendMail is kept
as a "hiden" option for experienced users.
That  means  there is a parameter  named "SendMailMethod"  set to 0 by
default ; setting it manually to 1 switches to SendMail
Added multicast support
Merge pull request #85 from Ptizef/master

Remove duplicated code and change Send Mail logic for Unix plateforms
Merge pull request #86 from stripydog/master

Added multicast support
Language update
Correct MSW and OSX build errors for Datastream UDP Multicast support.
Language update
Extend PlugIn API 1.11
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN into mainline

Conflicts:
	include/datastream.h
	src/datastream.cpp
	src/pluginmanager.cpp