#251 properly implement "3rd gender"

[Alexander Schuch]

There are three value of the user's sex at the moment:
male, female and bot. However, the bot has no own
personal pronoun.

Using the English language file, male users are
referred to as "he/him", female ones as "she/her", but
bots (still) as "him/her", example:

Q was also very polite: 1120 voices from him/her.

I expect to read an "it" there. However, in the
configuration file, Q is listed with the following entry:

<user nick="Q" sex="b"></user>