[SysApps] Fixed halfclose handling on RawSockets

Set the readyStatus accordingly and remove the event that
doesn't exist anymore.
[SysApps] Fixed TCPSocket attribute defaults
[SysApps] Update halfclose() handling to match the spec
Merge pull request #1689 from tmpsantos/tcpsocket_nits

[SysApps] Fixes small nits on the TCPSocket API