Position reporting, refactored system variables, serial print fixes, updated streaming scripts.

- Added machine position reporting to status queries. This will be
further developed with part positioning/offsets and maintaining
location upon reset.

- System variables refactored into a global struct for better
readability.

- Removed old obsolete Ruby streaming scripts. These were no longer
compatible. Updated Python streaming scripts.

- Fixed printFloat() and other printing functions.

- Decreased planner buffer back to 18 blocks and increased TX serial
buffer to 64 bytes. Need the memory space for future developments.

- Begun adding run-time modes to grbl, where block delete toggle, mm/in
reporting modes, jog modes, etc can be set during runtime. Will be
fleshed out and placed into EEPROM when everything is added.

script/Obsolete/stream.rb

@@ -0,0 +1,50 @@
+require 'rubygems'
+require 'optparse'
+require 'serialport'
+
+
+options_parser = OptionParser.new do |opts|
+  opts.banner = "Usage: stream [options] gcode-file"
+  opts.on('-v', '--verbose', 'Output more information') do
+    $verbose = true
+  end   
+
+  opts.on('-p', '--prebuffer', 'Prebuffer commands') do
+    $prebuffer = true
+  end   
+  
+  opts.on('-h', '--help', 'Display this screen') do
+    puts opts
+    exit
+  end
+end
+options_parser.parse!
+if ARGV.empty?
+  puts options_parser
+  exit
+end
+
+# SerialPort.open('/dev/tty.FireFly-A964-SPP-1', 115200) do |sp|
+SerialPort.open('/dev/tty.usbserial-A700e0GO', 9600) do |sp|
+  sp.write("\r\n\r\n");
+  sleep 1
+  ARGV.each do |file|
+    puts "Processing file #{file}"
+    prebuffer = $prebuffer ? 20 : 0
+    File.readlines(file).each do |line|
+      next if line.strip == ''
+      puts line.strip
+      sp.write("#{line.strip}\r\n");
+      if prebuffer == 0
+        begin
+          result = sp.gets.strip
+          puts "Grbl >> #{result}" #unless result == 'ok'
+        end while !(result =~ /^ok|^error/)
+      else
+        prebuffer -= 1
+      end
+    end
+  end
+  puts "Done."
+  sleep 500
+end