if the alias is not delimited in ADQL.

This commit fixes the GitHub issue #56

this table is declared with an alias. Instead, the table alias must be used.

Note: This problem occurred only when ADQLParser was used with a DBChecker.

This commit fixes the GitHub issue #53

sub-query. Without this information, it was impossible to resolve columns makingreference to sub-queries of the clause FROM. See the JUnit test case for a
concrete example.
(error raised by Hendrik Heinl - ARI/GAVO)