Add page protections test

Merge pull request libriscv#49 from fwsGonzo/new_release

Release work

Add information about remote GDB

Add Go program

Add 64-bit support for MULH-family instructions

Document 64-bit support

Remove shared Page attribute, use non_owning instead

Add sqrt/pow tests for F/D extensions

Fix gettimeofday needs 32-bit structure

Add setup script with suggestive comments