Fix docs for makedirs_perms

Make documentation for makedirs_perms show mode 0755 instead of 493
use zmq.IPC_PATH_MAX_LEN constant

less code duplication
better language
Update docstring for set_timezone
Add function to compare timezones
Give FreeBSD a helpful warning on get_zone
Fix timezone state to do more accurate check
Forgot to actually use md5sum to check zones
PEP-8 fix as per s0undt3ch
Because I'm feeling nice, fixing punctuation for @giantlock
Merge pull request #3447 from techhat/issue3446

Fix timezone state to do more accurate check
Remove crypto abstract

The crypto design docs have not yet been finalized, this document
is not entirely accurate and was written early on for the zeromq
team just as an abstract on the crypto routine
Apparently md5 is deprecated in favor of hashlib
Merge pull request #3448 from techhat/issue3446

Apparently md5 is deprecated in favor of hashlib
fix typo in docstring
Merge pull request #3451 from giantlock/develop

fix typo in docstring
Merge pull request #3452 from seanchannel/develop

install from @madduck
Fix import typo in rpm build patch
Fix #3456
minor spacing change
Merge pull request #3443 from viq/patch-1

Fix docs for makedirs_perms