Fix addnode "onetry": Connect with OpenNetworkConnection
Add CODESEPARATOR/FindAndDelete() tests
Fix incorrect checkpoint data for testnet3
remove CWallet::AddReserveKey which is never used
remove CTransaction::IsNewerThan which is never used
remove LogException( ) which is never used
remove LookupHostNumeric( ) which is never used
remove GetMedianTime( ) which is never used
remove CPubKey::VerifyCompact( ) which is never used
add DEFAULT_UPNP constant in net

- as this is a shared Core/GUI setting, this makes it easier to keep them
  in sync (also no new includes are needed)
Doc: Always use absolute paths
Remove redundant c_str
Remove forward declaration for non-existent class CCoinsDB

Found by stephenreed on #bitcoin.dev.
Update test_main.cpp

i think should delete （#include "bitcoin-config.h"）。
Replace non-threadsafe strerror

Log the name of the error as well as the error code if a network problem
happens. This makes network troubleshooting more convenient.

Use thread-safe strerror_r and the WIN32 equivalent FormatMessage.
Merge pull request #4166

b641c9c Fix addnode "onetry": Connect with OpenNetworkConnection (Cozz Lovan)
Merge pull request #4212

d90491a Update test_main.cpp (LongShao007)
Replace non-threadsafe gmtime and setlocale

Make DateTimeStrFormat use boost::posix_time.

Also re-enable the util_DateTimeStrFormat tests, as they are no
longer platform specific.
Merge pull request #4152

3e8ac6a Replace non-threadsafe gmtime and setlocale (Wladimir J. van der Laan)
a60838d Replace non-threadsafe strerror (Wladimir J. van der Laan)
Add Tips and Tricks section to README