Refactor common waiting code in throttle.py
Refactor common waiting code in throttle.py

Both lag() and __call__() shared the exact same code to wait for some
seconds and eventually announce the delay.  Refactor the code to a new
method throttle.wait(seconds).

Change-Id: Id1d34357ec04caac17bea120c0d079ce8a5a3dbe

TridevGuha/pywikibot-core,Darkdadaah/pywikibot-core,jayvdb/pywikibot-core,smalyshev/pywikibot-core,PersianWikipedia/pywikibot-core,trishnaguha/pywikibot-core,jayvdb/pywikibot-core,npdoty/pywikibot,happy5214/pywikibot-core,VcamX/pywikibot-core,wikimedia/pywikibot-core,icyflame/batman,npdoty/pywikibot,wikimedia/pywikibot-core,happy5214/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core,hasteur/g13bot_tools_new,hasteur/g13bot_tools_new,valhallasw/pywikibot-core,Darkdadaah/pywikibot-core,magul/pywikibot-core,h4ck3rm1k3/pywikibot-core,darthbhyrava/pywikibot-local,h4ck3rm1k3/pywikibot-core,xZise/pywikibot-core,emijrp/pywikibot-core