Simple map lister implementation (concommand: maps) & Small vs fixes

[fuzun]

Added a temporary map lister function until real one gets developed. (This is pretty decent for now.) It is not very good to put it in filesystem.c but it uses some private(static) filesystem functions.

Screenshot: https://vgy.me/yme5X3.png

&&&

Some vs warning fixes, should not bother anyone.

[a1batross]

Try to use FS_Search.

[fuzun]

FS_Search tries to look everywhere in gamedir? I saw it but did not use because it seem to be heavier at first.

[mittorn]

Something like:

FS_Search( va( "maps/*%s*.bsp", Cmd_Argv( 1 ) ), true );

[fuzun]

@a1batross @mittorn Is this approach better?

[mittorn]

Q_strncpy and other string functions in xash3d always adds '\0' to the end of string

[fuzun]

@mittorn Can you check the latest commit? Modify if you want and decide for implementation as it is becoming rotten as time passes.

Is there a similar command? Maybe an alias can be made instead of this.

[a1batross]

I think this can be merged.