x509.js update

• LICENSE.txt small update for years of copyright.
• ext/x64-core*.js was missed and added
• x509 1.1.6 to 1.1.7
  • X509.{getHexOfTLV_V3ExtValue,getHexOfV_V3ExtValue}
    are chageed to return null instead of '' if there
    is no extension specified by name or oid.
  • X509.getBasicConstraints added
  • X509.getSignatureAlgorithmName added
  • X509.getSignatureValueHex added
  • API document update
• each *.min.js files are moved to min/ folder.
• clean up old *-all-min.js