[Xcb] about api changes

[Thomas Hunger]

Hello,

I want to warm up this topic, at least for the changes which I'd like 
to introduce for sure. No. 2 would break the current API! It would be 
great if someone sees any problems/additions now. Then we would not 
need to break the API again.

1) Remove the xxx_request_t structures from the headers. They are only
   needed internally to pack data for requests. The opcode-defines
   could go as well. Are they useful for anything? 

2) New naming conventions in structs/replies. The field-names in
   replies and structs (e.g. nameLen-> name_len in xprint.xml). This
   could be solved in two ways: a) apply naming filter to all names or 
   b) write them correctly in the xml files.

   Solution b) has the advantage that in the case someone really needs
   a name which is not coherent with the naming convention, she could
   introduce it.

Tom