Fix: Line number calculation in the lexer

	modified:   ocaml/lexer.mll
Fix: Avoid duplicate compilation

	modified:   ocaml/alba.ml
Some comments edited

	modified:   ocaml/term_builder.ml
Fix: Synchronisation of type variables

The number of type variables for untyped variables have to be
syncronized properly between the context and the term builders
at entering the building of a lambda expression and completing
a lamda expression.

	modified:   ocaml/typer.ml
Fix: Term capture in 'Term_table.unify_with'

Bound variables must not be taken out of its binding definition.

	modified:   ocaml/term_table.ml
	modified:   ocaml/term_table.mli
'ghost' included into the parent type

But not yet used.

	modified:   ocaml/ast.ml
	modified:   ocaml/parser.mly
	modified:   ocaml/support.ml