Cvars: Adjust few things

- Hook is not as post, because allowing blocking change is not really that useful and this makes a context more simpler.
- Setting a min bound > max bound and reversely throw an error
- set_pcvar_bounds set cvar value on new min/max bound.
- Remove error "A cvar can't be binded with several variables", it's okay to no error such situation.

public/memtools/CDetour/detourhelpers.h

@@ -34,7 +34,7 @@
 
 #if defined(__linux__) || defined(__APPLE__)
 	#include <sys/mman.h>
-    #include <unistd.h>
+	#include <unistd.h>
 	#ifndef PAGE_SIZE
 		#define	PAGE_SIZE	4096
 	#endif