cleanup/define spec for 1.0

[joreg]

• ~reconsider UInts in the spec. (eg. ID, string length,...array length)~

• ~compound types~

• ~arrays: how to define array of array of ...~

• ~filetree~

• ~include dictionaries?~

• ~dynamic/fixed arrays?~

• ~vectors of all subtypes?~

• ~do we need unsigned types except byte?~

• ~image?~

• ~Groups have children or parameters have parents?~

  • ~on protocol level parameters have parents, on API-Level ParameterGroups have children.~
  • ~root param with no ID (size-prefix = 0) always exists: need to define that user cannot create a param with that ID~