Annotate every send/receive operation in Exec.hs
Annotate every send/receive operation in Exec.hs

The 'debug' log messages are now added as annotations to any I/O errors
during these operations, so if an error occurs, it'll be possible to
exactly identify the location from the error message.

Signed-off-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>
Reviewed-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>

leshchevds/ganeti,bitemyapp/ganeti,leshchevds/ganeti,leshchevds/ganeti,ganeti/ganeti,andir/ganeti,grnet/snf-ganeti,dimara/ganeti,yiannist/ganeti,yiannist/ganeti,bitemyapp/ganeti,yiannist/ganeti,grnet/snf-ganeti,onponomarev/ganeti,andir/ganeti,andir/ganeti,onponomarev/ganeti,ganeti/ganeti,mbakke/ganeti,mbakke/ganeti,mbakke/ganeti,ganeti/ganeti,dimara/ganeti