minor code cleanup

Signed-off-by: Swizzy <swizzy@hotmail.co.uk>
Converted StripNonHex to pure Regex instead
Converted StripHexIdentifier to pure Regex, making it ONLY match the first 0x, anything else is invalid...
Added IsIPv4 a simple Regex method to verify that a string is a valid IPv4 IPAddress :)

Signed-off-by: Swizzy <swizzy@hotmail.co.uk>