Write fee estimate and peers files only when initialized

Fixes #4669.

Move the loading of addresses to StartNode() to make it more
self-contained.
rpc-tests: don't spew non-errors to stdout

There's a brief race here, the process might've already exited and cleaned up
after itself. If that's the case, reading from the pidfile will harmlessly
fail. Keep those quiet.
Typo in test
Merge pull request #5080

e21b2e0 Typo in test (Luke)
Merge pull request #5074

005b5af rpc-tests: don't spew non-errors to stdout (Cory Fields)
Merge pull request #4942

9406471 Write fee estimate and peers files only when initialized (Wladimir J. van der Laan)
boost: drop dependency on is_fundamental in serialization

There's only one case where a vector containing a fundamental type is
serialized all-at-once, unsigned char. Anything else would lead to
strange results.

Use a dummy argument to overload in that case.
boost: drop dependency on tuple in serialization

There's only one user of this form of serialization, so it can be easily
dropped. It could be re-added if desired when we switch to c++11.
boost: remove CPrivKey dependency from CECKey

This allows CECKey to be used without directly depending on the secure
allocators
boost: drop boost dependency in core.cpp
boost: drop boost dependency in utilstrencodings.cpp
boost: drop boost dependency in version.cpp.

Also add a test to verify.
Merge pull request #5082

5f4bcf6 boost: drop boost dependency in version.cpp. (Cory Fields)
352058e boost: drop boost dependency in utilstrencodings.cpp (Cory Fields)
e1c9467 boost: drop boost dependency in core.cpp (Cory Fields)
e405aa4 boost: remove CPrivKey dependency from CECKey (Cory Fields)
5295506 boost: drop dependency on tuple in serialization (Cory Fields)
1d9b86d boost: drop dependency on is_fundamental in serialization (Cory Fields)