Support strings for cli defines deсlaration

[CrazyHackGUT]

Add support for definition string as defines. SPComp has support declare defines from console arguments, like:

./spcomp NAME=VALUE sourcecode.sp

But passing string as values doesn't supported.

[assyrianic]

possible precursor to sourcepawn templates?

[dvander]

#define is not really something we want to encourage more of.

[Headline]

@dvander

The primary use case for this is for versioning of sp scripts in ci environments. I agree with you, but this specific situation seems justified to me.