fix memory leaks when parse error-recovering/error-reporting
remove preprecessor macros ANTLR_BEGIN_NAMESPACE/ANTLR_END_NAMESPACE
Cleanup

- unused #define macros removed
- unused class templates removed
- unused #include-s removed
avoid various compiler warnings on various platforms
Sync tests with latest changes

= note: macros ANTLR_ENC_* are no more used
=       use enums antlr3::ENC_* instead
Force all enum values (including EOF_TOKEN) to be unsigned

- removes compiler warning