This commit adds tools to test parsing of WML macros by the preprocessor
and parser. The commit also adds two tests of the #define and #undef
WML macro as examples.
The tests consist of three steps:
1. Define one WML string containing macros and one WML string
that lacks macros in each test. The two WML strings should be
equivalent after preprocessing.
2. Transform each WML string into a syntax tree (represented by config
objects) with the preprocessor and parser of Wesnoth.
3. Check if the two config objects are equal. Since the two WML strings
are equivalent, the two configs object should be equivalent if the
preprocessor and parsers are both correct.
The output of the preprocessor is in an undocumented format. Therefore,
this commit does not test the preprocessor as an isolated unit.
These were emptied out when SDL 1.2 was removed (358bd1235f07d8d577). I seem to recall
someone saying it might be worth keeping them around in case something needed to be put
back, but it's been a year and a half. Not much worth in keeping empty files.
This quells warnings from CMake about reserved target names, and reduces confusion about which `test` is intended: the wesnoth executable or the standard shell command.
