Scripts: Modify copyright string variable

Update the string that will be inserted to LilyPond files as license preamble
Scripts: Update generated LaTeX commands

The LaTeX commands don't need starred and non-starred versions anymore.
Scripts: Adjust generated LaTeX test code to non-starred commands

the commands don't use starred and non-starred versions anymore,
instead curly brackets.
Update the test text to reflect this
Scripts: Make path operations OS-independent (genGlyphCommands)

Use os.path.join wherever needed.
This has been updated and tested for genGlyphCommands.py only.
buildglyphimages has to be done separately.
genGlyphCommands.py: Use arbitrary (given) directory

The input and output files aren't expected in dedicated folders anymore.
Instead the script simply takes a reference to a file as an example
and writes the output file in the same directory
Merge branch 'gen-glyph-commands'