Merge tag 'v0.5.1' into experimental

Version 0.5.1
Restored experimental/dev info
bundle install
bundle update arachni
Scan#start: Set status to active *after* the RPC call
Profile#to_rpc_options: Sanitize with Arachni::Options.hash_to_rpc_data
Scan: Added #starting?
scans/show_inactive: Show initializing msg for #starting? scans
Dispatcher: Un-cache RPC clients of deleted or unreachable Dispatchers
Scan: Improved logging of RPC errors

[Issue #455]
scans/show_inactive: Show real status for initializing/starting scans
Dispatcher#preferred: Only include reachable Dispatchers
bundle update
config/application.rb: Added Arachni::Reactor error logging
bundle update arachni
bundle update arachni
scans/show_inactive: Fixed HTML syntax
Profile#to_rpc_options: Only use the configured input values
bundle update arachni
bundle update arachni