refactor / optimizations: feebumper

[sanjaykdragon]

Minor optimization - stop calling GetHash so much

[theStack]

Both CWalletTx::GetHash() and CTransaction::GetHash() are just simple getter-methods returning the value of a member variable (i.e. not computing anything) and both of them are implemented in their header files, enabling inlining, hence I highly doubt that this is bringing any performance improvement.

[sanjaykdragon]

Both CWalletTx::GetHash() and CTransaction::GetHash() are just simple getter-methods returning the value of a member variable (i.e. not computing anything) and both of them are implemented in their header files, enabling inlining, hence I highly doubt that this is bringing any performance improvement.

Didn't know that, thought that GetHash did some computations