#742 Cannot cross-compile gutenprint

[Ross Burton]

It's impossible to easily cross-compile gutenprint as src/xml/xmli18n-tmp.h is generated at build time using extract-strings, which in cross builds will be built with the cross compiler.

The usual solution here is to use autoconf-archive's CC_FOR_BUILD macros, which let you use a potentially different compiler for specific tools which need to be ran on the build host.

Of course, the fact that extract-strings links to a fairly large chunk of the library is an issue, but it's fairly simple to just ignore the library and build the sources needed directly.