Add relative timestamps when logging to stderr
Add relative timestamps when logging to stderr

Makes it easier to see time difference between messages when running
mce in debug modes.

android-808/mce,kimmoli/mce,maikelwever/mce,mlehtima/mce,maikelwever/mce,kimmoli/mce,spiiroin/mce,kimmoli/mce,maikelwever/mce,android-808/mce,maikelwever/mce,mlehtima/mce,mlehtima/mce,spiiroin/mce,spiiroin/mce,spiiroin/mce,android-808/mce,mikkoharju/mce,mikkoharju/mce,mlehtima/mce,kimmoli/mce,mikkoharju/mce,mikkoharju/mce,android-808/mce