os/server: Fix indentation
os/server: Fix TCP connection

- remove unused errno
- remove unused port_end
- correct calculation of addr_len
- use correct string length during IP copy
os/server: Fix possible port overflow

- add documentation about port being optional
- parse port into long and check for valid value
Merge #874 'fix TCP connection (issue #870)'
vim-patch:7.4.341

Problem:    sort() doesn't handle numbers well.
Solution:   Add an argument to specify sorting on numbers. (Christian Brabandt)

https://code.google.com/p/vim/source/detail?r=adc4a84f72eb44dae657af713922a6e2c1f64ae3