Update boards.txt
Merge pull request #377 from KeithV/master

fixed serial to use more than just _SER0_VECTOR
Merge pull request #375 from majenkotech/patch-1

Update boards.txt
removed the asking for platform. There is an alternate way to do this. Resolved issue #372.
Switched CDC to using line status to determine endpoint presence.
Added USBSerial operator int() to test for USB connectivity (a-la Leonardo)
Merge pull request #378 from majenkotech/master

Switched CDC to using line status to determine endpoint presence.
upload max was sized too small, sized for USB not FTDI