Fixed: added proposed changes to lax NetMQFrame

proposed changes by @somdoron for issue #52

Fixed: Corrected the unit test but still unsure if this is the expected result.
Merge pull request #54 from tobi-tobsen/bug_#52_ReqToRouter_Fix

Fixed: added proposed changes to lax NetMQFrame
fix a bug in the router with the router mandatory feature
Fixed a bug in the tcp connector causing exceptions and too may file descriptor
Merge pull request #55 from somdoron/bug_fixes

Bug fixes
Merge branch 'master' of https://github.com/tobi-tobsen/netmq