install.texi (avr): Replace incomplete list of supported MCU types with a link to...

install.texi (avr): Replace incomplete list of supported MCU types with a link to the current one ...

	* install.texi (avr): Replace incomplete list of supported MCU
	types with a link to the current one ...
	* invoke.texi (AVR Options): ... here.  Update -mmcu= to list
	all supported MCU types.  Document -minit-stack= default.
	Document new options -mno-tablejump, -mtiny-stack.
	* md.texi (AVR family):  Fix typo in 'w' constraint letter
	description.  Document 'q'.  Update 'O'.

From-SVN: r37917