www/squid_radius_auth: Refactor and moved manpages

• Moved manpages to share/man
• Make it to respect CC/CFLAGS/LDFLAGS env vars
• Replace Make.inc patch by a simple REINPLACE_CMD just replacing = by ?= for desired variables and pass them using MAKE_ENV
• Use ALL_TARGET instead of patching Make.inc
• Use @sample for config file

Sponsored by: Rubicon Communications, LLC ("Netgate")