ETF: updated list of issues related to encoding

The updated list:

  #1 "illegal char encoding"
 #18 "top-level is unclear"
 #29 "non-serializable data"
#144 "array metainformation not xml-ish"
#159 "wording in section 4.1.1"
#161 "array member as an independent element"
#163 "Multi-reference 'id' attribute - NOT a real ID"
#164 "mapping of encoding to Schema and back"

Editorial:
 #17 "encoding usage discussion needed"
 #48 "custom encoding styles"
 #47 "data model vs. encoding"
 #55 "examples needed"
#129 "examples needed"
#117 "position and offset clarification"
#162 "arrayType production rules"

IMHO does not pertain to data encoding:
 #59 "character encoding"