This refactors the tolower/toupper code to use standards-conformant logic, and also adds some helpful utility functions. Regular tolower/toupper must be supplied a value that can be represented as `unsigned char`, but the std:: functions are a bit more robust.
This allows to mark certain functions or virtvars to be declared as
"deprecated" starting with a specific engine version. What this means is
that a special message will be added to the documentation stating since
when the function is deprecated and can contain an optional message. The
actual enforcement of the deprecation depends on the target version of
the mod so that we can stay backwards compatible.
If the mod supports the version since when the function is deprecated,
it will not be added to the Lua state which means that it doesn't exist
for the calling script. If the targetted version is before the stated
version, the function will still be added to the Lua state.
As the first function to use this feature, I have deprecated
createParticle in the testing library and moved it to the graphics
library with a new name reflecting that it creates a persistent
particle. I also added the corresponding function for adding a
non-persistent particle.
This fixes various issues I found while trying to compile FSO in a cross
compilation setup using MinGW. This is a prerequisite for merging Tea-CI
support.
Goober5000