Allow specifying of doctrine template implementations, closes #864
merge 7eebb2d90ff325e7ea54fdf8dd8e4a23db9b085d...107076cd5364006cab8e58d09e8c30c8c9534e52 (from 0.11)
made _common.xsl more modular, with callable templates for migrating elements to new namespcaes and separate templates for each envelope element
fixed copy/paste mistake in 4edf0cd82b2ee65953dbf8ed284de278531eedc0
fixed copy/paste errors in comments