Typos

[cwfoo]

• Section 4.7 Problems with signals:

  However the problem is that the signals that are received between the instant were the behavior is automatically reset to Signal_default and the moment were set_signal is invoked ...

  Typo: "were" should be "where" instead.

• Section 6.12 High-level primitives:

  If the client closes the connection cleanly, the child gets and end of file on the input channel ...

  Typo: "and" should be "an" instead.