Do not share SocketBase across tasks

[Tygre]

I was using the Miami SDK. Naively, I used to declare a global SocketBase shared across files… and tasks! This sharing across tasks sometimes would cause crashes when two tasks were using a same SocketBase. These crashes became obvious when I tried to factor out the code opening the library. I should have RTFM’ed: it clearly states that “The recommended approach, if several Processes need to use the "bsdsocket.library" functions, is to reopen the library for every user.”
Make sure that tasks do not share a common SocketBase!

[Tygre]

Thank you AmigaOS and AROS developers for explaining the cause of the crashes and providing a solution!

[Tygre]

The solution is (1) replace the Miami SDK with the Roadwho one, which allows compiling with SocketBase global variable and (2) use the TASKSOCKBASE include to define SocketBase as FindTask(NULL)->tc_UserData.

[Tygre]

Worked on stability, especially wrt. sockets. Fixed #111, #113, and #114

→ <<cset ed2c99136650>>

[Tygre]

Worked on stability, especially wrt. sockets. Fixed #111, #113, and #114

→ <<cset bbba268cf188>>