windows - set process priority class to ABOVE_NORMAL_PRIORITY_CLASS previous default was NORMAL_PRIORITY_CLASS before today

add timerfd support to the core for now you must enable it in switch.conf.xml with the param enable-softtimer-timerfd=true later if it proves to work well we can make it on by default, please test if you have a new kernel that supports this option kernel >= 2.6.25 and libc >= 2.8

revert 44bfcf1d this breaks the build for everyone who does not have python-dev package

FS-3172 this also fixes the incorrect usage of L16 on payload 10 which may or may not break interop with other sip devices if we do it right.  also added rtp_disable_byteswap variable that can be set to false to disable byteswap when a device is encountered that is incompat (inluding all precious version of FS up till now)