ep128emu 2.0.4 release

Changes in version 2.0.4:

* keyboard map can be configured with the GUI
* external game devices like joysticks and gamepads are supported, and can be assigned in the keyboard map like normal keys
* video and audio output can be recorded to AVI files
* it is now possible to use audio files (WAV, AIFF, etc.) as tape images, with support for all tape features except markers; a simple linear phase FIR filter can also be applied to the input signal
* improved television vertical sync emulation
* new command line option for loading a snapshot or demo file on start-up
* added hue shift to the display options
* emulation speed percentage and floppy drive LEDs are now displayed on the GUI; it is also possible to change the emulation speed
* various minor bug fixes and improvements