plus4emu 1.2.7 release

Changes in version 1.2.7:

* added support for using the mouse to change the cursor position in the emulated machine, and copying text to and pasting from the clipboard; the following functions are available:
- left click: sets the cursor position
- right click: sets the cursor position, and copies the selected word to the clipboard
- ctrl + right click: sets the cursor position, and copies text from the selected line to the clipboard
- shift + right click: copies text from the whole screen to the clipboard without changing the cursor position
- middle click: sets the cursor position, and pastes text from the clipboard
- shift + middle click: pastes text from the clipboard without changing the cursor position
Note that these are disabled when a display mode that hides the menu bar and the mouse cursor is selected, or light pen emulation - which also uses the mouse - is enabled.
* new command line option (-keybuf) for typing text of any length at startup; the text can also be read from a file
* added machine configuration option to control the SID output volume; this also affects the sound recorded to AVI files
* increased TED audio output level relative to the default SID output level, for better accuracy in programs that use both types of sound at the same time
* minor sound emulation fixes
* the process priority of the emulator can be changed from the GUI (currently, this is only implemented on Windows)
* some utility improvements: 'compress' has more options now, and is optimized somewhat for slightly better efficiency and speed; 'p4fliconv' automatically detects the use of the C64 palette in GIF files and enables pixel exact reading mode, and there is a new experimental hires conversion algorithm as well
* minor optimizations
* in OpenGL video mode, the vertical interlace effect is now also displayed at quality 1 and 2, and quality 2 uses 32-bit textures for improved color accuracy at the expense of being somewhat slower (previously, both interlace and 32-bit textures were enabled only at quality 3)
* fixed bug that prevented the emulator display from being correctly redrawn when damaged on Windows in software video mode or OpenGL with the quality set to 0
* a few Linux compile and link errors have been fixed