Add %un[i]macro, and a few stylistic cleanups.
Note: unlike %undef, %un[i]macro takes an argument specification,
which must *exactly* match the macro being undefined. Similarly,
%unimacro has to be used to undefine a macro defined with %imacro, and
vice versa.
I noticed there was no sane way to concatenate the contents of quoted
strings, so add the %strcat directive.
These really need to become preprocessor functions at some stage.
Add a builtin equivalent to the %include directive called %use.
%use includes a standard macro file compiled into the binary; these
come from the macros/ directory in the source code.
The idea here is to be able to provide optional macro packages with
the distribution, without adding complex host filesystem dependencies.
- Add %warning directive
- Only unquote an %error or %warning string if it is the only thing on
the directive line.
- Don't expand macros inside a quoted string, even for %error.
Introduce new preprocessor directives %depend and %pathsearch, and
make incbin a standard macro using these filenames. This lets us
remove the code that makes incbin search the path.
