all is PHONY.
'all' means to make the .xsls from the .xsltxts.
Use find; dump Emacs backup files.
Anything unhandled yields a fatal error.
Remove useless variable.
Drop xsltxt.jar.
GNU Makefile, please.
clean is also phony.
If compilation fails, then the whole thing fails.
Target variable.
First dependency variable.
Use built-in functions to express the targets.
Option to preserve comments.
Recognize text elements and comments.  Allow option to normalize whitespace.
Whitespace.