nodogsplash: Release 4.2.0 (#513)

nodogsplash: Release 4.2.0 (#513)

Maintainer: Moritz Warning <moritzwarning@web.de>

Compiled and tested on snapshot SDK mips_24kc and arm_cortex-a7_neon-vfpv4

This release adds significant functionality in the form of capturing the client User-Agent string and passing to both PreAuth and BinAuth scripts. Compatibility is maintained with previous versions.

Changelog since last OpenWrt release:

 * BinAuth - Send User Agent string and client-ip to the binauth script [bluewavenet]
 * BinAuth - Update the two example BinAuth scripts showing use of passed arguments [bluewavenet]
 * Documentation - Update BinAuth section [bluewavenet]
 * PreAuth - Send User Agent string to the preauth script [bluewavenet]
 * PreAuth - Update the example PreAuth script showing use of passed arguments [bluewavenet]
 * Documentation - Update PreAuth section [bluewavenet]
 * BinAuth - Send redir variable to the binauth script, allow passing of custom variable payload [bluewavenet]
 * BinAuth - Provide two example BinAuth scripts [bluewavenet]
 * Documentation - Rework Binauth section plus numerous minor updates [bluewavenet]
 * Deprecate RedirectURL config option as it is rendered obsolete by many CPD implementations, use FAS instead [bluewavenet]
 * Numerous minor updates to html, css and script files [bluewavenet]
 * Fix bug - faskey, exit gracefully if not set and fas_secure_enabled = 2 [bluewavenet]
 * Fix bug - Systemd, Do not set debug level in nodogsplash.service [bluewavenet]
 * Fix bug - ndsctl, delete lock file if NDS is not started [bluewavenet]

Signed-off-by: Rob White <rob@blue-wave.net>