- no longer caching bitfield information but accessing it directly
  when needed
- removed all kludges for bitfield handling
- reused BOOL parameter to codeview_get_type for monitoring
  traces (will be used in later patches)

- now that we have offset tables to type, we can cleanly
  parse the field-lists and remove the associated kludges
- also adding internal structure for easing parameter sharing
  across functions (codeview_type_parse)
- in mscvpdb.h, also reparated the type records that are
  referenced from other type records (union codeview_type_ref)
  from type records referenced by symbols (union codeview_type)

- enforce the type records that can be accessed by symbols (these are
  anyway the high level ones)

- our engine for parsing types section now requires in entry
  an offsets table for getting directly to each type in the
  section
- (re)construct this table for PDB types

- added definitions for start_search symbol info
- silenced warnings from this symbol

- in MSC debug info parsing, clearly separate a source file
  information from a compiland (including in linetab structure)
- in ELF debug info parsing, now storing compiland directly
  in symtab_elt while browsing the symtab section (we still
  create twice the compilands, once in stabs/dwarf parsing, 
  a second time in symtab parsing)

A void return type is represented by a FC_END/FC_PAD sequence in the
proc format string. Increment the proc offset by two when a function
returns void.

- DBGHELP_NOLIVE env variable is tested earlier to avoid 
  some strange effects in live target detection
- in WineDbg, delete DBGHELP_NOLIVE before attaching to
  a process, because we know it must be a live target

This should ensure that we do the right thing in the build dir even if
WINEDLLPATH isn't set.