Documentation of the content of the %vars hash which is the only way to 
transport ship information between various installer menus and the main
program.

1) collections and schemes
--------------------------
selected collections/schemes
	collection-<collection> 0|1		OUT
	scheme-<scheme> 0|1			OUT
total number of collections
	n_collections_available 84		IN
and the number of collections selected:
	n_collections_selected 1		OUT
the selected scheme
	selected_scheme scheme-<scheme>		OUT


2) platforms
------------
location of the arch
	diskbin_<arch-os> 0|1			IN/OUT
	netbin_<arch-os> 0|1			IN/OUT
the current one
	inst_platform <arch-os>			IN
the current platform ???
	this_platform <arch-os>			IN
number of systems available in total
	n_systems_available 15			IN
number of systems selected
	n_systems_selected 3			OUT


3) options
----------
build all formats
	option_fmt 0|1				OUT
letter instead of A4
	option_letter 0|1			OUT
install symlinks (on unix)
	option_symlinks 0|1			OUT
and the respective destinations for the symlinks
	sys_info <path/to/info/dir>		OUT
	sys_bin /usr/local/bin			OUT
	sys_man /usr/local/man			OUT
do install the doc files
	option_doc 0|1				OUT
do install the src files
	option_src 0|1				OUT
destination paths
	TEXMFSYSVAR /home/norbert/tltest/2008/texmf-var		OUT
	TEXDIR /home/norbert/tltest/2008			OUT
	TEXMFLOCAL /home/norbert/tltest/texmf-local		OUT
	TEXMFHOME ~/texmf					OUT

4) other stuff ???
------------------
total size to be used
	total_size 54		DEDUCED
no idea ????
	page 0


NEW LAYOUT
==========

%MediaData = (
	media => CD|DVD|NET
	location => /path/to/master | base-url
	release => NNNN
	tlpdb => the respective tlpdb
	all_collections => [ ... ]
	std_collections => [ ... ]
	lang_collections => [ ... ]
	lang_doc_collections => [ ... ]
	schemes => [ ... ]
	n_collections => NN
	n_schemes => NN
	diskbins => [ ... ]
	netbins => [ ... ]
	n_systems_available => NN   (== #(#diskbins u #netbins))
	this_platform => <arch-os>
)

%vars = (
	systems => [ ... ] 	  # those selected for installation
	collections => [ ... ]	  # those selected for installation
	selected_scheme => scheme-<scheme>
	option_fmt => 0|1
	option_letter 0|1			OUT
	option_symlinks 0|1			OUT
	sys_info <path/to/info/dir>		OUT
	sys_bin /usr/local/bin			OUT
	sys_man /usr/local/man			OUT
	option_doc 0|1				OUT
	option_src 0|1				OUT
	TEXMFSYSVAR /home/norbert/tltest/2008/texmf-var		OUT
	TEXDIR /home/norbert/tltest/2008			OUT
	TEXMFLOCAL /home/norbert/tltest/texmf-local		OUT
	TEXMFHOME ~/texmf					OUT
)
