BerkeleyDB dump files have key and value lines indented.
The salvage code passes these to ParseHex as-is.
Check this in the tests (should just pass with current code).
- fixes #3136
- the problem is related to Boost path and a static initialized internal
pointer
- using a std::string in CDBEnv::EnvShutdown() prevents the problem
- this removes the boost::filesystem::path path field from CDBEnv