qt: Show weeks as well as years behind for long timespans
qt: Show weeks as well as years behind for long timespans

Closes #3811.

Conflicts:
	src/qt/locale/bitcoin_en.ts

Conflicts:

	src/qt/bitcoingui.cpp

robvanmieghem/clams,nochowderforyou/clams,thunderrabbit/clams,Jheguy2/Mercury,Kefkius/clams,nochowderforyou/clams,Kefkius/clams,Jheguy2/Mercury,nochowderforyou/clams,nochowderforyou/clams,Jheguy2/Mercury,thunderrabbit/clams,dooglus/clams,robvanmieghem/clams,dooglus/clams,thunderrabbit/clams,Kefkius/clams,Jheguy2/Mercury,nochowderforyou/clams,robvanmieghem/clams,dooglus/clams,dooglus/clams,Kefkius/clams,Jheguy2/Mercury,thunderrabbit/clams,dooglus/clams,robvanmieghem/clams,robvanmieghem/clams,thunderrabbit/clams,Kefkius/clams