Added command-line parameters

For output filters, continuous output, choose device file.
README updated: explain command line switches
Rasperry pi rev 2's I2C port is bcm2708_i2c.1
Pull the reading logic out of main()
Handle I2C bus names containing spaces
With both -T and -H options, show temp and humidity
Specify the device name with the -d option

To make the specification of a device or bus name more uniform.
Specify the I2C slave address with the -a option
Update the README and munin_plugin.sh for option changes
Doesn't look like github is going to fix the README precedence issue

Github used to prefer README.md to README, so if README.md was a
symlink to README then it would render README as markdown.  Now it
seems to prefer README, and renders it as plain text.

Which is ugly, so drop README and just have README.md.
Added command-line parameters: output filters, continuous output, choose device file
Merge branch 'master' of https://github.com/pierinz/hygrochip-linux

Conflicts:
	README
	hyt-read.c