fix remaining issues in #6, with some other tweaks

Moved GetFullVersion() into hexer namespace, moved declaration to
Processor.hpp (defintion is in Processor.cpp), and added HEXER_DLL.

Also removed 'using namespace std' to clean up the global namespace,
which required explicit includes for things such as string, vector, etc.
Merge branch 'master' into unresolved_basic_string
need to include before checking define