Credit does NOT decrease equity accounts

http://en.wikipedia.org/wiki/Debits_and_credits#Aspects_of_transactions

Improve explanation
Minor Improvements of Guide/Overview: oview-featuresintl2

E.g. update number of partial supported languages
Korrigierte Fassung von ch_basics basierend auf
https://github.com/Mechtilde/gnucash-docs/tree/trunk/guide/de
Korrigierte Fassung von ch_oview basierend auf
https://github.com/Mechtilde/gnucash-docs/tree/trunk/guide/de
Update of translators in gnucash-guide-de.omf
Merge branch 'maint'