UI: Clear command for Log Console

Added Log Console with a context menu holding "Copy" and "Clear", overriding the original one (which has Undo,Cut,Paste). Now you can just rightclick on the Log and select Clear to clear the log console. This may give you a better view sometimes.

I'm very sorry for my accidentally closed that pull. It is in fact trying to use the same information to commit and push failed (cause the remote is not behind my local.. in deed the two commits are not the same). added the missing header for wxTextDataObject (which used in Copy command)

I'm thinking for using more strict checking rules on VS..