added many rpc wallet tests

deleted the empty no throw test in rpc_wallet_tests line 65

fixed some comments

starting verify tests

finished verify message tests

changed some comments
[Qt] ensure payment request network matches client network

- replaces checks in SendCoinsDialog::handlePaymentRequest() that belong
  to PaymentServer (normal URIs are special cased, as only an isValid
  check is done on BTC addresses)
- prevents the client to handle payment requests that do not match the
  clients network and shows an error instead (mainly a problem with
  drag&drop payment requests onto the client window)
- includes some small comment changes also
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
Remove unused imports in macdeploy script
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)
Add missing LOCK(cs_main)
Doc: Always use absolute paths
gitian: Add OSX build descriptors

Github-Pull: #4185
Rebased-By: Wladimir J. van der Laan
Rebased-From: bb5da27, 2288206, 7fe8fe6, f76db78, ebcf375, fa1ed7c, 397e9b8
qt: Periodic language update
Merge pull request #4204

305ccaa Add missing LOCK(cs_main) (Pieter Wuille)
Remove redundant c_str
Remove forward declaration for non-existent class CCoinsDB

Found by stephenreed on #bitcoin.dev.