Add the algorithm header to a few FifoPlayer cpp files.

Both of them use std::min and std::max, but this header wasn't included.
Remove unnecessary wxT declarations in FifoPlayerDlg.
These are not needed anymore since wx 3.0. Also some minor formatting stuff.
Fix assertion fails in FifoPlayerDlg.cpp.
Merge pull request #229 from lioncash/fifoplayer

Fix FIFO Player dialog assertion failures (aka work around wx's inability to handle size_t correctly).