Support for new configuration

[1.2.0] - 2017-24-04

• Support custom header for user-agent

Features Enhancement

• Added .axd files extentions to whitelist files
• Sending px_orig_value when decryption fails

v1.1.0

• Moved server url to new URL
• New design for block pages
• Block page customisation
• Support for classic pipeline mode

v1.0

Update README's contributing