Version 2.3.0

• Bugfix: Handle the case of incomplete DWARF type info
  C allows incomplete type declarations. For example "struct foo;" without a definition only tells the compiler that his type exists, and results in a stub type entry with the attribute DW_AT_declaration in the DWARF data.
• upgrade to a2lfile 2.3.1
  • change the behavior of merge for GROUPS and FUNCTION
    Previously, if two GROUPS in a merge had the same name, then the incoming group was renamed with the suffix ".MERGE".
    Now the content for GROUPs/FUNCTIONs with the same name is combined.
  • a2l checker improvements: fix several bugs, and handle some additional cases
• In strict mode, any problems detected by --check now cause a2ltool to exit with an error code.
  Outside of strict mode, --check remains informational.