Merge pull request #898 from C-o-r-E/master

Major improvements on the Windows and OS X server
check or propagate return values when writing
Merge pull request #899 from hardening/hardening6

check or propagate return values when writing
don't free xkb_layout or xkb_variant when it has not been set
call time instead of gmtime (makes valgrind happy)
Merge pull request #902 from hardening/hardening7

Corrections found by Valgrind
always initialize lpMultiByteStr parameter when calling ConvertFromUnicode
Merge pull request #903 from hardening/hardening7

initialize lpMultiByteStr parameter when calling ConvertFromUnicode
libfreerdp-core: fix server crash when accepting NLA connections
Merge pull request #905 from mfleisz/master

libfreerdp-core: fix server crash when accepting NLA connections
Correctly treat error case and memory management
libfreerdp-core: change fastpath return codes
libfreerdp-core/peer: remove a printf message.
wfreerdp: enable fullscreen toggling even started in window mode.
Frame acknowledgement should be sent by client UI.
Fixed padding management
Merge pull request #908 from llyzs/llyzs

Frame acknowledgement should be sent by client UI.
Merge pull request #906 from hardening/hardening8

Correctly treat error case and memory management when reading certificate
Added error messages when orders processing fails
Added a check for exponent_length
Added error messages for certificate parsing
libfreerdp-core: added reference counter for receive buffers