(bug 65309) check whether page already exist, code improvements
(bug 65309) check whether page already exist, code improvements

- check whether page already exist
- new core Bot style to handle options
- show options in doc string and with -help option
- new touch option to make a null edit on a page
- unicode strings for operator messages with variable contents

Change-Id: I2c574ace865ecc422524cd6682818297c326c750

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